1380638813 has 4 divisors (see below), whose sum is σ = 1380994140. Its totient is φ = 1380283488.

The previous prime is 1380638789. The next prime is 1380638821. The reversal of 1380638813 is 3188360831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3188360831 = 89 ⋅35824279.

It can be written as a sum of positive squares in 2 ways, for example, as 848090884 + 532547929 = 29122^2 + 23077^2 .

It is a cyclic number.

It is not a de Polignac number, because 1380638813 - 2⁸ = 1380638557 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 (1380638863) 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, 171770 + ... + 179627.

It is an arithmetic number, because the mean of its divisors is an integer number (345248535).

Almost surely, 2^1380638813 is an apocalyptic number.

It is an amenable number.

1380638813 is a deficient number, since it is larger than the sum of its proper divisors (355327).

1380638813 is an equidigital number, since it uses as much as digits as its factorization.

1380638813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355326.

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 1380638813 is about 37156.9483811575. The cubic root of 1380638813 is about 1113.5080457664.

The spelling of 1380638813 in words is "one billion, three hundred eighty million, six hundred thirty-eight thousand, eight hundred thirteen".