21973725 has 36 divisors (see below), whose sum is σ = 40027572. Its totient is φ = 11520000.

The previous prime is 21973697. The next prime is 21973729. The reversal of 21973725 is 52737912.

It can be written as a sum of positive squares in 6 ways, for example, as 127449 + 21846276 = 357^2 + 4674^2 .

It is not a de Polignac number, because 21973725 - 2¹⁰ = 21972701 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21973725.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21973729) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 12925 + ... + 14525.

It is an arithmetic number, because the mean of its divisors is an integer number (1111877).

Almost surely, 2^21973725 is an apocalyptic number.

21973725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21973725 is a deficient number, since it is larger than the sum of its proper divisors (18053847).

21973725 is a wasteful number, since it uses less digits than its factorization.

21973725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1678 (or 1670 counting only the distinct ones).

The product of its digits is 26460, while the sum is 36.

The square root of 21973725 is about 4687.6139986138. The cubic root of 21973725 is about 280.0923377430.

The spelling of 21973725 in words is "twenty-one million, nine hundred seventy-three thousand, seven hundred twenty-five".