20677557 has 4 divisors (see below), whose sum is σ = 27570080. Its totient is φ = 13785036.

The previous prime is 20677549. The next prime is 20677577. The reversal of 20677557 is 75577602.

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 not a de Polignac number, because 20677557 - 2³ = 20677549 is a prime.

It is a super-2 number, since 2×20677557² = 855122726976498, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20677507) 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, 3446257 + ... + 3446262.

It is an arithmetic number, because the mean of its divisors is an integer number (6892520).

Almost surely, 2^20677557 is an apocalyptic number.

It is an amenable number.

20677557 is a deficient number, since it is larger than the sum of its proper divisors (6892523).

20677557 is an equidigital number, since it uses as much as digits as its factorization.

20677557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6892522.

The product of its (nonzero) digits is 102900, while the sum is 39.

The square root of 20677557 is about 4547.2581848846. The cubic root of 20677557 is about 274.4730714358.

The spelling of 20677557 in words is "twenty million, six hundred seventy-seven thousand, five hundred fifty-seven".