21572375 has 32 divisors (see below), whose sum is σ = 30438720. Its totient is φ = 15120000.

The previous prime is 21572363. The next prime is 21572387. The reversal of 21572375 is 57327512.

It is an interprime number because it is at equal distance from previous prime (21572363) and next prime (21572387).

It is not a de Polignac number, because 21572375 - 2⁴ = 21572359 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39605 + ... + 40145.

It is an arithmetic number, because the mean of its divisors is an integer number (951210).

Almost surely, 2^21572375 is an apocalyptic number.

21572375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21572375 is a deficient number, since it is larger than the sum of its proper divisors (8866345).

21572375 is a wasteful number, since it uses less digits than its factorization.

21572375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 596 (or 586 counting only the distinct ones).

The product of its digits is 14700, while the sum is 32.

The square root of 21572375 is about 4644.6070877955. The cubic root of 21572375 is about 278.3765535411.

Adding to 21572375 its reverse (57327512), we get a palindrome (78899887).

The spelling of 21572375 in words is "twenty-one million, five hundred seventy-two thousand, three hundred seventy-five".