20505677 has 4 divisors (see below), whose sum is σ = 20942016. Its totient is φ = 20069340.

The previous prime is 20505643. The next prime is 20505679. The reversal of 20505677 is 77650502.

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 20505677 - 2¹⁸ = 20243533 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 (20505679) 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, 218099 + ... + 218192.

It is an arithmetic number, because the mean of its divisors is an integer number (5235504).

Almost surely, 2^20505677 is an apocalyptic number.

It is an amenable number.

20505677 is a deficient number, since it is larger than the sum of its proper divisors (436339).

20505677 is an equidigital number, since it uses as much as digits as its factorization.

20505677 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436338.

The product of its (nonzero) digits is 14700, while the sum is 32.

The square root of 20505677 is about 4528.3194454455. The cubic root of 20505677 is about 273.7104449983.

The spelling of 20505677 in words is "twenty million, five hundred five thousand, six hundred seventy-seven".