20657725 has 18 divisors (see below), whose sum is σ = 28160090. Its totient is φ = 15021600.

The previous prime is 20657717. The next prime is 20657743. The reversal of 20657725 is 52775602.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 1490841 + 19166884 = 1221^2 + 4378^2 .

It is not a de Polignac number, because 20657725 - 2³ = 20657717 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 390 + ... + 6439.

Almost surely, 2^20657725 is an apocalyptic number.

20657725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20657725 is a deficient number, since it is larger than the sum of its proper divisors (7502365).

20657725 is a wasteful number, since it uses less digits than its factorization.

20657725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6861 (or 6845 counting only the distinct ones).

The product of its (nonzero) digits is 29400, while the sum is 34.

The square root of 20657725 is about 4545.0770070484. The cubic root of 20657725 is about 274.3852936399.

It can be divided in two parts, 206577 and 25, that added together give a palindrome (206602).

The spelling of 20657725 in words is "twenty million, six hundred fifty-seven thousand, seven hundred twenty-five".