18539620401 has 32 divisors (see below), whose sum is σ = 25806635008. Its totient is φ = 11825896320.

The previous prime is 18539620399. The next prime is 18539620403. The reversal of 18539620401 is 10402693581.

It is an interprime number because it is at equal distance from previous prime (18539620399) and next prime (18539620403).

It is not a de Polignac number, because 18539620401 - 2¹ = 18539620399 is a prime.

It is a super-2 number, since 2×18539620401² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18539620401.

It is not an unprimeable number, because it can be changed into a prime (18539620403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3623421 + ... + 3628533.

It is an arithmetic number, because the mean of its divisors is an integer number (806457344).

Almost surely, 2^18539620401 is an apocalyptic number.

It is an amenable number.

18539620401 is a deficient number, since it is larger than the sum of its proper divisors (7267014607).

18539620401 is a wasteful number, since it uses less digits than its factorization.

18539620401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5581.

The product of its (nonzero) digits is 51840, while the sum is 39.

The spelling of 18539620401 in words is "eighteen billion, five hundred thirty-nine million, six hundred twenty thousand, four hundred one".