20177918401 has 3 divisors (see below), whose sum is σ = 20178060451. Its totient is φ = 20177776352.

The previous prime is 20177918389. The next prime is 20177918407. The reversal of 20177918401 is 10481977102.

The square root of 20177918401 is 142049.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 2556801 + 20175361600 = 1599^2 + 142040^2 .

It is not a de Polignac number, because 20177918401 - 2²⁵ = 20144363969 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20177918407) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 71025 + ... + 213073.

Almost surely, 2^20177918401 is an apocalyptic number.

20177918401 is the 142049-th square number.

20177918401 is the 71025-th centered octagonal number.

It is an amenable number.

20177918401 is a deficient number, since it is larger than the sum of its proper divisors (142050).

20177918401 is an frugal number, since it uses more digits than its factorization.

20177918401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284098 (or 142049 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 40.

Multiplying 20177918401 by its product of nonzero digits (28224), we get a square (569501568949824 = 23864232²).

The spelling of 20177918401 in words is "twenty billion, one hundred seventy-seven million, nine hundred eighteen thousand, four hundred one".