21310275 has 24 divisors (see below), whose sum is σ = 40267264. Its totient is φ = 9741600.

The previous prime is 21310271. The next prime is 21310279. The reversal of 21310275 is 57201312.

It is an interprime number because it is at equal distance from previous prime (21310271) and next prime (21310279).

It is not a de Polignac number, because 21310275 - 2² = 21310271 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21310271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19771 + ... + 20820.

Almost surely, 2^21310275 is an apocalyptic number.

21310275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21310275 is a deficient number, since it is larger than the sum of its proper divisors (18956989).

21310275 is a wasteful number, since it uses less digits than its factorization.

21310275 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40611 (or 40606 counting only the distinct ones).

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 21310275 is about 4616.3053408543. The cubic root of 21310275 is about 277.2445502464.

Adding to 21310275 its reverse (57201312), we get a palindrome (78511587).

The spelling of 21310275 in words is "twenty-one million, three hundred ten thousand, two hundred seventy-five".