20671538177 has 8 divisors (see below), whose sum is σ = 21449100456. Its totient is φ = 19905495552.

The previous prime is 20671538123. The next prime is 20671538179. The reversal of 20671538177 is 77183517602.

It is a Cunningham number, because it is equal to 143776²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 3194962576 + 17476575601 = 56524^2 + 132199^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 20671538177 - 2³⁴ = 3491668993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20671538179) 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, 2876258 + ... + 2883435.

It is an arithmetic number, because the mean of its divisors is an integer number (2681137557).

Almost surely, 2^20671538177 is an apocalyptic number.

It is an amenable number.

20671538177 is a deficient number, since it is larger than the sum of its proper divisors (777562279).

20671538177 is an equidigital number, since it uses as much as digits as its factorization.

20671538177 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5759827.

The product of its (nonzero) digits is 493920, while the sum is 47.

The spelling of 20671538177 in words is "twenty billion, six hundred seventy-one million, five hundred thirty-eight thousand, one hundred seventy-seven".