21930375 has 16 divisors (see below), whose sum is σ = 36492768. Its totient is φ = 11696000.

The previous prime is 21930371. The next prime is 21930379. The reversal of 21930375 is 57303912.

It is an interprime number because it is at equal distance from previous prime (21930371) and next prime (21930379).

It is not a de Polignac number, because 21930375 - 2² = 21930371 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21930371) 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, 28866 + ... + 29615.

It is an arithmetic number, because the mean of its divisors is an integer number (2280798).

Almost surely, 2^21930375 is an apocalyptic number.

21930375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21930375 is a deficient number, since it is larger than the sum of its proper divisors (14562393).

21930375 is an equidigital number, since it uses as much as digits as its factorization.

21930375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58499 (or 58489 counting only the distinct ones).

The product of its (nonzero) digits is 5670, while the sum is 30.

The square root of 21930375 is about 4682.9878282994. The cubic root of 21930375 is about 279.9080267651.

The spelling of 21930375 in words is "twenty-one million, nine hundred thirty thousand, three hundred seventy-five".