20657697 has 4 divisors (see below), whose sum is σ = 27543600. Its totient is φ = 13771796.

The previous prime is 20657677. The next prime is 20657699. The reversal of 20657697 is 79675602.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20657697 - 2⁷ = 20657569 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20657699) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3442947 + ... + 3442952.

It is an arithmetic number, because the mean of its divisors is an integer number (6885900).

Almost surely, 2^20657697 is an apocalyptic number.

It is an amenable number.

20657697 is a deficient number, since it is larger than the sum of its proper divisors (6885903).

20657697 is an equidigital number, since it uses as much as digits as its factorization.

20657697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6885902.

The product of its (nonzero) digits is 158760, while the sum is 42.

The square root of 20657697 is about 4545.0739267915. The cubic root of 20657697 is about 274.3851696703.

The spelling of 20657697 in words is "twenty million, six hundred fifty-seven thousand, six hundred ninety-seven".