21972275 has 12 divisors (see below), whose sum is σ = 29341872. Its totient is φ = 16225440.

The previous prime is 21972271. The next prime is 21972277. The reversal of 21972275 is 57227912.

It is not a de Polignac number, because 21972275 - 2² = 21972271 is a prime.

It is a hoax number, since the sum of its digits (35) 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 (21972271) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 33479 + ... + 34128.

It is an arithmetic number, because the mean of its divisors is an integer number (2445156).

Almost surely, 2^21972275 is an apocalyptic number.

21972275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21972275 is a deficient number, since it is larger than the sum of its proper divisors (7369597).

21972275 is a wasteful number, since it uses less digits than its factorization.

21972275 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67630 (or 67625 counting only the distinct ones).

The product of its digits is 17640, while the sum is 35.

The square root of 21972275 is about 4687.4593331569. The cubic root of 21972275 is about 280.0861767056.

The spelling of 21972275 in words is "twenty-one million, nine hundred seventy-two thousand, two hundred seventy-five".