1157993591 has 4 divisors (see below), whose sum is σ = 1158061872. Its totient is φ = 1157925312.

The previous prime is 1157993587. The next prime is 1157993597. The reversal of 1157993591 is 1953997511.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1953997511 = 463 ⋅4220297.

It is a cyclic number.

It is not a de Polignac number, because 1157993591 - 2² = 1157993587 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1157993597) 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, 12950 + ... + 49836.

It is an arithmetic number, because the mean of its divisors is an integer number (289515468).

Almost surely, 2^1157993591 is an apocalyptic number.

1157993591 is a deficient number, since it is larger than the sum of its proper divisors (68281).

1157993591 is an equidigital number, since it uses as much as digits as its factorization.

1157993591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68280.

The product of its digits is 382725, while the sum is 50.

The square root of 1157993591 is about 34029.3048856423. The cubic root of 1157993591 is about 1050.1114291419. Note that the first 3 decimals are identical.

The spelling of 1157993591 in words is "one billion, one hundred fifty-seven million, nine hundred ninety-three thousand, five hundred ninety-one".