20515522401 has 16 divisors (see below), whose sum is σ = 33156400320. Its totient is φ = 12433649760.

The previous prime is 20515522351. The next prime is 20515522483. The reversal of 20515522401 is 10422551502.

20515522401 is a `hidden beast` number, since 20 + 51 + 552 + 2 + 40 + 1 = 666.

It is not a de Polignac number, because 20515522401 - 2⁹ = 20515521889 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20515522301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34537620 + ... + 34538213.

It is an arithmetic number, because the mean of its divisors is an integer number (2072275020).

Almost surely, 2^20515522401 is an apocalyptic number.

It is an amenable number.

20515522401 is a deficient number, since it is larger than the sum of its proper divisors (12640877919).

20515522401 is a wasteful number, since it uses less digits than its factorization.

20515522401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69075853 (or 69075847 counting only the distinct ones).

The product of its (nonzero) digits is 4000, while the sum is 27.

The spelling of 20515522401 in words is "twenty billion, five hundred fifteen million, five hundred twenty-two thousand, four hundred one".