21992275 has 6 divisors (see below), whose sum is σ = 27270452. Its totient is φ = 17593800.

The previous prime is 21992273. The next prime is 21992293. The reversal of 21992275 is 57229912.

It is not a de Polignac number, because 21992275 - 2¹ = 21992273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21992273) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 439821 + ... + 439870.

Almost surely, 2^21992275 is an apocalyptic number.

21992275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21992275 is a deficient number, since it is larger than the sum of its proper divisors (5278177).

21992275 is an equidigital number, since it uses as much as digits as its factorization.

21992275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 879701 (or 879696 counting only the distinct ones).

The product of its digits is 22680, while the sum is 37.

The square root of 21992275 is about 4689.5921997547. The cubic root of 21992275 is about 280.1711326294.

The spelling of 21992275 in words is "twenty-one million, nine hundred ninety-two thousand, two hundred seventy-five".