17977911605 has 4 divisors (see below), whose sum is σ = 21573493932. Its totient is φ = 14382329280.

The previous prime is 17977911571. The next prime is 17977911607. The reversal of 17977911605 is 50611977971.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50611977971 = 79 ⋅640657949.

It can be written as a sum of positive squares in 2 ways, for example, as 10842223876 + 7135687729 = 104126^2 + 84473^2 .

It is not a de Polignac number, because 17977911605 - 2¹⁰ = 17977910581 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 (17977911607) 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, 1797791156 + ... + 1797791165.

It is an arithmetic number, because the mean of its divisors is an integer number (5393373483).

Almost surely, 2^17977911605 is an apocalyptic number.

It is an amenable number.

17977911605 is a deficient number, since it is larger than the sum of its proper divisors (3595582327).

17977911605 is an equidigital number, since it uses as much as digits as its factorization.

17977911605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3595582326.

The product of its (nonzero) digits is 833490, while the sum is 53.

The spelling of 17977911605 in words is "seventeen billion, nine hundred seventy-seven million, nine hundred eleven thousand, six hundred five".