1157839381 has 4 divisors (see below), whose sum is σ = 1157911564. Its totient is φ = 1157767200.

The previous prime is 1157839363. The next prime is 1157839391. The reversal of 1157839381 is 1839387511.

1157839381 is a nontrivial binomial coefficient, being equal to C(48122, 2).

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1046199025 + 111640356 = 32345^2 + 10566^2 .

It is a 3-Lehmer number, since φ(1157839381) divides (1157839381-1)³.

It is a cyclic number.

It is not a de Polignac number, because 1157839381 - 2⁷ = 1157839253 is a prime.

It is a super-4 number, since 4×1157839381⁴ (a number of 37 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a deceptive number, since it divides R_1157839380.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1157839301) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1 + ... + 48121.

It is an arithmetic number, because the mean of its divisors is an integer number (289477891).

It is a Poulet number, since it divides 2^1157839380-1.

Almost surely, 2^1157839381 is an apocalyptic number.

1157839381 is the 48121-st triangular number and also the 24061-st hexagonal number.

1157839381 is the 16041-st centered nonagonal number.

It is an amenable number.

1157839381 is a deficient number, since it is larger than the sum of its proper divisors (72183).

1157839381 is an equidigital number, since it uses as much as digits as its factorization.

1157839381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72182.

The product of its digits is 181440, while the sum is 46.

The square root of 1157839381 is about 34027.0389690317. The cubic root of 1157839381 is about 1050.0648126281.

The spelling of 1157839381 in words is "one billion, one hundred fifty-seven million, eight hundred thirty-nine thousand, three hundred eighty-one".