21628214520 has 128 divisors (see below), whose sum is σ = 74508768000. Its totient is φ = 4967239680.

The previous prime is 21628214479. The next prime is 21628214537. The reversal of 21628214520 is 2541282612.

It is a Harshad number since it is a multiple of its sum of digits (33).

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, 406105 + ... + 456264.

It is an arithmetic number, because the mean of its divisors is an integer number (582099750).

Almost surely, 2^21628214520 is an apocalyptic number.

21628214520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21628214520 is an abundant number, since it is smaller than the sum of its proper divisors (52880553480).

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

21628214520 is a wasteful number, since it uses less digits than its factorization.

21628214520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 862413 (or 862409 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 33.

The spelling of 21628214520 in words is "twenty-one billion, six hundred twenty-eight million, two hundred fourteen thousand, five hundred twenty".