20724925 has 24 divisors (see below), whose sum is σ = 28338464. Its totient is φ = 14938560.

The previous prime is 20724889. The next prime is 20724929. The reversal of 20724925 is 52942702.

It is not a de Polignac number, because 20724925 - 2⁷ = 20724797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20724929) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13234 + ... + 14716.

Almost surely, 2^20724925 is an apocalyptic number.

20724925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20724925 is a deficient number, since it is larger than the sum of its proper divisors (7613539).

20724925 is a wasteful number, since it uses less digits than its factorization.

20724925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1549 (or 1544 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 20724925 is about 4552.4636187453. The cubic root of 20724925 is about 274.6824985834.

The spelling of 20724925 in words is "twenty million, seven hundred twenty-four thousand, nine hundred twenty-five".