20421340566656 has 32 divisors (see below), whose sum is σ = 41372684161200. Its totient is φ = 10037608071424.

The previous prime is 20421340566631. The next prime is 20421340566691. The reversal of 20421340566656 is 65666504312402.

It is a tau number, because it is divible by the number of its divisors (32).

It is a super-4 number, since 4×20421340566656⁴ (a number of 54 digits) contains 4444 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1352040950 + ... + 1352056053.

Almost surely, 2^{20421340566656} is an apocalyptic number.

It is an amenable number.

20421340566656 is an abundant number, since it is smaller than the sum of its proper divisors (20951343594544).

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

20421340566656 is an equidigital number, since it uses as much as digits as its factorization.

20421340566656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2704097076 (or 2704097064 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 50.

The spelling of 20421340566656 in words is "twenty trillion, four hundred twenty-one billion, three hundred forty million, five hundred sixty-six thousand, six hundred fifty-six".