20657425 has 12 divisors (see below), whose sum is σ = 26499420. Its totient is φ = 15955520.

The previous prime is 20657423. The next prime is 20657437. The reversal of 20657425 is 52475602.

It can be written as a sum of positive squares in 6 ways, for example, as 263169 + 20394256 = 513^2 + 4516^2 .

It is not a de Polignac number, because 20657425 - 2¹ = 20657423 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20657423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13522 + ... + 14971.

It is an arithmetic number, because the mean of its divisors is an integer number (2208285).

Almost surely, 2^20657425 is an apocalyptic number.

20657425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20657425 is a deficient number, since it is larger than the sum of its proper divisors (5841995).

20657425 is a wasteful number, since it uses less digits than its factorization.

20657425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28532 (or 28527 counting only the distinct ones).

The product of its (nonzero) digits is 16800, while the sum is 31.

The square root of 20657425 is about 4545.0440041874. The cubic root of 20657425 is about 274.3839653880.

The spelling of 20657425 in words is "twenty million, six hundred fifty-seven thousand, four hundred twenty-five".