20520804177664 has 144 divisors (see below), whose sum is σ = 46946134144000. Its totient is φ = 8769668124672.

The previous prime is 20520804177623. The next prime is 20520804177689. The reversal of 20520804177664 is 46677140802502.

It is a super-2 number, since 2×20520804177664² (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, 1018442662 + ... + 1018462810.

Almost surely, 2^{20520804177664} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20520804177664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23473067072000).

20520804177664 is an abundant number, since it is smaller than the sum of its proper divisors (26425329966336).

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

20520804177664 is a wasteful number, since it uses less digits than its factorization.

20520804177664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21758 (or 21744 counting only the distinct ones).

The product of its (nonzero) digits is 4515840, while the sum is 52.

The spelling of 20520804177664 in words is "twenty trillion, five hundred twenty billion, eight hundred four million, one hundred seventy-seven thousand, six hundred sixty-four".