18911980671 has 8 divisors (see below), whose sum is σ = 25235633280. Its totient is φ = 12598157592.

The previous prime is 18911980663. The next prime is 18911980699. The reversal of 18911980671 is 17608911981.

It is a happy number.

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

It is not a de Polignac number, because 18911980671 - 2³ = 18911980663 is a prime.

It is a super-2 number, since 2×18911980671² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18911980601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2452891 + ... + 2460588.

It is an arithmetic number, because the mean of its divisors is an integer number (3154454160).

Almost surely, 2^18911980671 is an apocalyptic number.

18911980671 is a deficient number, since it is larger than the sum of its proper divisors (6323652609).

18911980671 is a wasteful number, since it uses less digits than its factorization.

18911980671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4914765.

The product of its (nonzero) digits is 217728, while the sum is 51.

The spelling of 18911980671 in words is "eighteen billion, nine hundred eleven million, nine hundred eighty thousand, six hundred seventy-one".