20657225 has 6 divisors (see below), whose sum is σ = 25614990. Its totient is φ = 16525760.

The previous prime is 20657209. The next prime is 20657233. The reversal of 20657225 is 52275602.

It can be written as a sum of positive squares in 3 ways, for example, as 3904576 + 16752649 = 1976^2 + 4093^2 .

It is not a de Polignac number, because 20657225 - 2⁴ = 20657209 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 413120 + ... + 413169.

It is an arithmetic number, because the mean of its divisors is an integer number (4269165).

Almost surely, 2^20657225 is an apocalyptic number.

20657225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20657225 is a deficient number, since it is larger than the sum of its proper divisors (4957765).

20657225 is an equidigital number, since it uses as much as digits as its factorization.

20657225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 826299 (or 826294 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 29.

The square root of 20657225 is about 4545.0220021470. The cubic root of 20657225 is about 274.3830798796.

The spelling of 20657225 in words is "twenty million, six hundred fifty-seven thousand, two hundred twenty-five".