20157977 has 8 divisors (see below), whose sum is σ = 23136000. Its totient is φ = 17204544.

The previous prime is 20157953. The next prime is 20157983. The reversal of 20157977 is 77975102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20157977 - 2²⁴ = 3380761 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20157977.

It is not an unprimeable number, because it can be changed into a prime (20157947) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4352 + ... + 7697.

It is an arithmetic number, because the mean of its divisors is an integer number (2892000).

Almost surely, 2^20157977 is an apocalyptic number.

It is an amenable number.

20157977 is a deficient number, since it is larger than the sum of its proper divisors (2978023).

20157977 is a wasteful number, since it uses less digits than its factorization.

20157977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12295.

The product of its (nonzero) digits is 30870, while the sum is 38.

The square root of 20157977 is about 4489.7635795218. The cubic root of 20157977 is about 272.1545807104.

The spelling of 20157977 in words is "twenty million, one hundred fifty-seven thousand, nine hundred seventy-seven".