21275075 has 24 divisors (see below), whose sum is σ = 28243728. Its totient is φ = 15841280.

The previous prime is 21275057. The next prime is 21275077. The reversal of 21275075 is 57057212.

21275075 = T₁₇₁ + T₁₇₂ + ... + T₅₀₉.

It is not a de Polignac number, because 21275075 - 2⁸ = 21274819 is a prime.

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21275077) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 47804 + ... + 48246.

It is an arithmetic number, because the mean of its divisors is an integer number (1176822).

Almost surely, 2^21275075 is an apocalyptic number.

21275075 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21275075 is a deficient number, since it is larger than the sum of its proper divisors (6968653).

21275075 is a wasteful number, since it uses less digits than its factorization.

21275075 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 583 (or 578 counting only the distinct ones).

The product of its (nonzero) digits is 4900, while the sum is 29.

The square root of 21275075 is about 4612.4911924035. The cubic root of 21275075 is about 277.0918166258.

The spelling of 21275075 in words is "twenty-one million, two hundred seventy-five thousand, seventy-five".