20677657 has 36 divisors (see below), whose sum is σ = 28539216. Its totient is φ = 14807520.

The previous prime is 20677649. The next prime is 20677663. The reversal of 20677657 is 75677602.

It is not a de Polignac number, because 20677657 - 2³ = 20677649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20677687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 90978 + ... + 91204.

It is an arithmetic number, because the mean of its divisors is an integer number (792756).

Almost surely, 2^20677657 is an apocalyptic number.

It is an amenable number.

20677657 is a deficient number, since it is larger than the sum of its proper divisors (7861559).

20677657 is a wasteful number, since it uses less digits than its factorization.

20677657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 278 (or 258 counting only the distinct ones).

The product of its (nonzero) digits is 123480, while the sum is 40.

The square root of 20677657 is about 4547.2691805082. The cubic root of 20677657 is about 274.4735139004.

Subtracting 20677657 from its reverse (75677602), we obtain a palindrome (54999945).

The spelling of 20677657 in words is "twenty million, six hundred seventy-seven thousand, six hundred fifty-seven".