20557426401 has 8 divisors (see below), whose sum is σ = 30455446560. Its totient is φ = 13704950916.

The previous prime is 20557426399. The next prime is 20557426411. The reversal of 20557426401 is 10462475502.

It is a happy number.

20557426401 is a `hidden beast` number, since 2 + 0 + 5 + 5 + 7 + 4 + 2 + 640 + 1 = 666.

It is not a de Polignac number, because 20557426401 - 2¹ = 20557426399 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20557426411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 380693055 + ... + 380693108.

It is an arithmetic number, because the mean of its divisors is an integer number (3806930820).

Almost surely, 2^20557426401 is an apocalyptic number.

It is an amenable number.

20557426401 is a deficient number, since it is larger than the sum of its proper divisors (9898020159).

20557426401 is an equidigital number, since it uses as much as digits as its factorization.

20557426401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 761386172 (or 761386166 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 36.

The spelling of 20557426401 in words is "twenty billion, five hundred fifty-seven million, four hundred twenty-six thousand, four hundred one".