21275275 has 24 divisors (see below), whose sum is σ = 30659744. Its totient is φ = 14342400.

The previous prime is 21275237. The next prime is 21275281. The reversal of 21275275 is 57257212.

It is not a de Polignac number, because 21275275 - 2⁹ = 21274763 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9679 + ... + 11671.

Almost surely, 2^21275275 is an apocalyptic number.

21275275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21275275 is a deficient number, since it is larger than the sum of its proper divisors (9384469).

21275275 is a wasteful number, since it uses less digits than its factorization.

21275275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2071 (or 2066 counting only the distinct ones).

The product of its digits is 9800, while the sum is 31.

The square root of 21275275 is about 4612.5128726108. The cubic root of 21275275 is about 277.0926849062.

The spelling of 21275275 in words is "twenty-one million, two hundred seventy-five thousand, two hundred seventy-five".