38557806781 has 4 divisors (see below), whose sum is σ = 41523791932. Its totient is φ = 35591821632.

The previous prime is 38557806767. The next prime is 38557806803. The reversal of 38557806781 is 18760875583.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18760875583 = 227 ⋅82647029.

It can be written as a sum of positive squares in 2 ways, for example, as 16156697881 + 22401108900 = 127109^2 + 149670^2 .

It is a cyclic number.

It is not a de Polignac number, because 38557806781 - 2⁷ = 38557806653 is a prime.

It is a super-2 number, since 2×38557806781² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (38557809781) 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, 1482992556 + ... + 1482992581.

It is an arithmetic number, because the mean of its divisors is an integer number (10380947983).

Almost surely, 2^38557806781 is an apocalyptic number.

It is an amenable number.

38557806781 is a deficient number, since it is larger than the sum of its proper divisors (2965985151).

38557806781 is a wasteful number, since it uses less digits than its factorization.

38557806781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2965985150.

The product of its (nonzero) digits is 11289600, while the sum is 58.

The spelling of 38557806781 in words is "thirty-eight billion, five hundred fifty-seven million, eight hundred six thousand, seven hundred eighty-one".