21620663306420 has 48 divisors (see below), whose sum is σ = 47567541278208. Its totient is φ = 8244374244480.

The previous prime is 21620663306399. The next prime is 21620663306479. The reversal of 21620663306420 is 2460336602612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 260197547 + ... + 260280626.

It is an arithmetic number, because the mean of its divisors is an integer number (990990443296).

Almost surely, 2^{21620663306420} is an apocalyptic number.

21620663306420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21620663306420 is an abundant number, since it is smaller than the sum of its proper divisors (25946877971788).

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

21620663306420 is a wasteful number, since it uses less digits than its factorization.

21620663306420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520478280 (or 520478278 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 41.

The spelling of 21620663306420 in words is "twenty-one trillion, six hundred twenty billion, six hundred sixty-three million, three hundred six thousand, four hundred twenty".