20979655 has 8 divisors (see below), whose sum is σ = 25239600. Its totient is φ = 16741056.

The previous prime is 20979641. The next prime is 20979671. The reversal of 20979655 is 55697902.

It is a happy number.

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-20979655 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3085 + ... + 7174.

It is an arithmetic number, because the mean of its divisors is an integer number (3154950).

Almost surely, 2^20979655 is an apocalyptic number.

20979655 is a deficient number, since it is larger than the sum of its proper divisors (4259945).

20979655 is a wasteful number, since it uses less digits than its factorization.

20979655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10673.

The product of its (nonzero) digits is 170100, while the sum is 43.

The square root of 20979655 is about 4580.3553355608. The cubic root of 20979655 is about 275.8032931164.

The spelling of 20979655 in words is "twenty million, nine hundred seventy-nine thousand, six hundred fifty-five".