20877557 has 4 divisors (see below), whose sum is σ = 20906400. Its totient is φ = 20848716.

The previous prime is 20877553. The next prime is 20877559. The reversal of 20877557 is 75577802.

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, and also an emirpimes, since its reverse is a distinct semiprime: 75577802 = 2 ⋅37788901.

It is a cyclic number.

It is not a de Polignac number, because 20877557 - 2² = 20877553 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 (20877551) 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, 13307 + ... + 14792.

It is an arithmetic number, because the mean of its divisors is an integer number (5226600).

Almost surely, 2^20877557 is an apocalyptic number.

It is an amenable number.

20877557 is a deficient number, since it is larger than the sum of its proper divisors (28843).

20877557 is an equidigital number, since it uses as much as digits as its factorization.

20877557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28842.

The product of its (nonzero) digits is 137200, while the sum is 41.

The square root of 20877557 is about 4569.1965376858. The cubic root of 20877557 is about 275.3551642461.

The spelling of 20877557 in words is "twenty million, eight hundred seventy-seven thousand, five hundred fifty-seven".