20779797 has 16 divisors (see below), whose sum is σ = 29695680. Its totient is φ = 12878592.

The previous prime is 20779789. The next prime is 20779799. The reversal of 20779797 is 79797702.

It is a happy number.

It is not a de Polignac number, because 20779797 - 2³ = 20779789 is a prime.

It is a super-2 number, since 2×20779797² = 863599926722418, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20779799) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1779 + ... + 6687.

It is an arithmetic number, because the mean of its divisors is an integer number (1855980).

Almost surely, 2^20779797 is an apocalyptic number.

It is an amenable number.

20779797 is a deficient number, since it is larger than the sum of its proper divisors (8915883).

20779797 is a wasteful number, since it uses less digits than its factorization.

20779797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5012.

The product of its (nonzero) digits is 388962, while the sum is 48.

The square root of 20779797 is about 4558.4862619076. The cubic root of 20779797 is about 274.9247044547.

The spelling of 20779797 in words is "twenty million, seven hundred seventy-nine thousand, seven hundred ninety-seven".