20125536643664 has 80 divisors (see below), whose sum is σ = 40569221736960. Its totient is φ = 9664831457280.

The previous prime is 20125536643633. The next prime is 20125536643673. The reversal of 20125536643664 is 46634663552102.

It is a super-2 number, since 2×20125536643664² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19355957 + ... + 20369195.

It is an arithmetic number, because the mean of its divisors is an integer number (507115271712).

Almost surely, 2^{20125536643664} is an apocalyptic number.

It is an amenable number.

20125536643664 is an abundant number, since it is smaller than the sum of its proper divisors (20443685093296).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20125536643664 is a wasteful number, since it uses less digits than its factorization.

20125536643664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1013788 (or 1013782 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 53.

The spelling of 20125536643664 in words is "twenty trillion, one hundred twenty-five billion, five hundred thirty-six million, six hundred forty-three thousand, six hundred sixty-four".