20538557001 has 24 divisors (see below), whose sum is σ = 29812217864. Its totient is φ = 13625418240.

The previous prime is 20538556777. The next prime is 20538557027. The reversal of 20538557001 is 10075583502.

20538557001 is a `hidden beast` number, since 2 + 0 + 5 + 3 + 85 + 570 + 0 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4523907600 + 16014649401 = 67260^2 + 126549^2 .

It is not a de Polignac number, because 20538557001 - 2²¹ = 20536459849 is a prime.

It is a super-2 number, since 2×20538557001² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20538557041) 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, 1634595 + ... + 1647111.

Almost surely, 2^20538557001 is an apocalyptic number.

It is an amenable number.

20538557001 is a deficient number, since it is larger than the sum of its proper divisors (9273660863).

20538557001 is a wasteful number, since it uses less digits than its factorization.

20538557001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13401 (or 13398 counting only the distinct ones).

The product of its (nonzero) digits is 42000, while the sum is 36.

The spelling of 20538557001 in words is "twenty billion, five hundred thirty-eight million, five hundred fifty-seven thousand, one".