18838625641 has 6 divisors (see below), whose sum is σ = 20706919226. Its totient is φ = 17126023200.

The previous prime is 18838625581. The next prime is 18838625653. The reversal of 18838625641 is 14652683881.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 14389202025 + 4449423616 = 119955^2 + 66704^2 .

It is a de Polignac number, because none of the positive numbers 2^k-18838625641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18838625671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 77845440 + ... + 77845681.

Almost surely, 2^18838625641 is an apocalyptic number.

18838625641 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18838625641 is a deficient number, since it is larger than the sum of its proper divisors (1868293585).

18838625641 is a wasteful number, since it uses less digits than its factorization.

18838625641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155691143 (or 155691132 counting only the distinct ones).

The product of its digits is 2211840, while the sum is 52.

The spelling of 18838625641 in words is "eighteen billion, eight hundred thirty-eight million, six hundred twenty-five thousand, six hundred forty-one".