21625216500 has 48 divisors (see below), whose sum is σ = 62972634816. Its totient is φ = 5766724000.

The previous prime is 21625216477. The next prime is 21625216513. The reversal of 21625216500 is 561252612.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7206906 + ... + 7209905.

It is an arithmetic number, because the mean of its divisors is an integer number (1311929892).

Almost surely, 2^21625216500 is an apocalyptic number.

21625216500 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21625216500 is an abundant number, since it is smaller than the sum of its proper divisors (41347418316).

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

21625216500 is a wasteful number, since it uses less digits than its factorization.

21625216500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14416833 (or 14416821 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The spelling of 21625216500 in words is "twenty-one billion, six hundred twenty-five million, two hundred sixteen thousand, five hundred".