20640555015 has 32 divisors (see below), whose sum is σ = 35711539200. Its totient is φ = 10140301824.

The previous prime is 20640554989. The next prime is 20640555073. The reversal of 20640555015 is 51055504602.

It is not a de Polignac number, because 20640555015 - 2⁵ = 20640554983 is a prime.

It is a super-2 number, since 2×20640555015² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 849115 + ... + 873084.

It is an arithmetic number, because the mean of its divisors is an integer number (1115985600).

Almost surely, 2^20640555015 is an apocalyptic number.

20640555015 is a deficient number, since it is larger than the sum of its proper divisors (15070984185).

20640555015 is a wasteful number, since it uses less digits than its factorization.

20640555015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1722271.

The product of its (nonzero) digits is 30000, while the sum is 33.

The spelling of 20640555015 in words is "twenty billion, six hundred forty million, five hundred fifty-five thousand, fifteen".