21292375 has 16 divisors (see below), whose sum is σ = 28619136. Its totient is φ = 15722400.

The previous prime is 21292367. The next prime is 21292391. The reversal of 21292375 is 57329212.

It is not a de Polignac number, because 21292375 - 2³ = 21292367 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 (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4927 + ... + 8176.

It is an arithmetic number, because the mean of its divisors is an integer number (1788696).

Almost surely, 2^21292375 is an apocalyptic number.

21292375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21292375 is a deficient number, since it is larger than the sum of its proper divisors (7326761).

21292375 is a wasteful number, since it uses less digits than its factorization.

21292375 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13131 (or 13121 counting only the distinct ones).

The product of its digits is 7560, while the sum is 31.

The square root of 21292375 is about 4614.3661536553. The cubic root of 21292375 is about 277.1669027642.

The spelling of 21292375 in words is "twenty-one million, two hundred ninety-two thousand, three hundred seventy-five".