21720023375 has 32 divisors (see below), whose sum is σ = 28612147200. Its totient is φ = 16415978400.

The previous prime is 21720023363. The next prime is 21720023387. The reversal of 21720023375 is 57332002712.

It is an interprime number because it is at equal distance from previous prime (21720023363) and next prime (21720023387).

It is not a de Polignac number, because 21720023375 - 2⁴ = 21720023359 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 859166 + ... + 884084.

It is an arithmetic number, because the mean of its divisors is an integer number (894129600).

Almost surely, 2^21720023375 is an apocalyptic number.

21720023375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21720023375 is a deficient number, since it is larger than the sum of its proper divisors (6892123825).

21720023375 is a wasteful number, since it uses less digits than its factorization.

21720023375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25320 (or 25310 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 32.

The spelling of 21720023375 in words is "twenty-one billion, seven hundred twenty million, twenty-three thousand, three hundred seventy-five".