21992625 has 48 divisors (see below), whose sum is σ = 40227408. Its totient is φ = 11558400.

The previous prime is 21992617. The next prime is 21992629. The reversal of 21992625 is 52629912.

It is a happy number.

21992625 is a `hidden beast` number, since 21 + 9 + 9 + 2 + 625 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 8946081 + 13046544 = 2991^2 + 3612^2 .

It is not a de Polignac number, because 21992625 - 2³ = 21992617 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21992625.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21992629) 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 47 ways as a sum of consecutive naturals, for example, 127039 + ... + 127211.

It is an arithmetic number, because the mean of its divisors is an integer number (838071).

Almost surely, 2^21992625 is an apocalyptic number.

21992625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21992625 is a deficient number, since it is larger than the sum of its proper divisors (18234783).

21992625 is a wasteful number, since it uses less digits than its factorization.

21992625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 307 (or 294 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 21992625 is about 4689.6295162838. The cubic root of 21992625 is about 280.1726188994.

The spelling of 21992625 in words is "twenty-one million, nine hundred ninety-two thousand, six hundred twenty-five".