20656997 has 8 divisors (see below), whose sum is σ = 20984832. Its totient is φ = 20332000.

The previous prime is 20656991. The next prime is 20657027. The reversal of 20656997 is 79965602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20656997 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 (20656991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17372 + ... + 18522.

It is an arithmetic number, because the mean of its divisors is an integer number (2623104).

Almost surely, 2^20656997 is an apocalyptic number.

It is an amenable number.

20656997 is a deficient number, since it is larger than the sum of its proper divisors (327835).

20656997 is a wasteful number, since it uses less digits than its factorization.

20656997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1419.

The product of its (nonzero) digits is 204120, while the sum is 44.

The square root of 20656997 is about 4544.9969196909. The cubic root of 20656997 is about 274.3820703931.

The spelling of 20656997 in words is "twenty million, six hundred fifty-six thousand, nine hundred ninety-seven".