21016513750 has 20 divisors (see below), whose sum is σ = 39393355716. Its totient is φ = 8406605000.

The previous prime is 21016513717. The next prime is 21016513753. The reversal of 21016513750 is 5731561012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21016513753) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 8405356 + ... + 8407855.

Almost surely, 2^21016513750 is an apocalyptic number.

21016513750 is a deficient number, since it is larger than the sum of its proper divisors (18376841966).

21016513750 is an equidigital number, since it uses as much as digits as its factorization.

21016513750 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16813233 (or 16813218 counting only the distinct ones).

The product of its (nonzero) digits is 6300, while the sum is 31.

It can be divided in two parts, 2101651 and 3750, that added together give a square (2105401 = 1451²).

The spelling of 21016513750 in words is "twenty-one billion, sixteen million, five hundred thirteen thousand, seven hundred fifty".