18635253681 has 24 divisors (see below), whose sum is σ = 28917719712. Its totient is φ = 10629731200.

The previous prime is 18635253677. The next prime is 18635253691.

18635253681 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 18635253681 - 2² = 18635253677 is a prime.

It is a super-2 number, since 2×18635253681² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 18635253681.

It is not an unprimeable number, because it can be changed into a prime (18635253691) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1503735 + ... + 1516076.

It is an arithmetic number, because the mean of its divisors is an integer number (1204904988).

Almost surely, 2^18635253681 is an apocalyptic number.

18635253681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18635253681 is a deficient number, since it is larger than the sum of its proper divisors (10282466031).

18635253681 is a wasteful number, since it uses less digits than its factorization.

18635253681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3019853 (or 3019842 counting only the distinct ones).

The product of its digits is 1036800, while the sum is 48.

The spelling of 18635253681 in words is "eighteen billion, six hundred thirty-five million, two hundred fifty-three thousand, six hundred eighty-one".