21502056500 has 48 divisors (see below), whose sum is σ = 46974869760. Its totient is φ = 8598189600.

The previous prime is 21502056497. The next prime is 21502056503. The reversal of 21502056500 is 565020512.

It is an interprime number because it is at equal distance from previous prime (21502056497) and next prime (21502056503).

It is a self number, because there is not a number n which added to its sum of digits gives 21502056500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21502056503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2999921 + ... + 3007079.

It is an arithmetic number, because the mean of its divisors is an integer number (978643120).

Almost surely, 2^21502056500 is an apocalyptic number.

21502056500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21502056500 is an abundant number, since it is smaller than the sum of its proper divisors (25472813260).

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

21502056500 is a wasteful number, since it uses less digits than its factorization.

21502056500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13185 (or 13173 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 26.

The spelling of 21502056500 in words is "twenty-one billion, five hundred two million, fifty-six thousand, five hundred".