18971490565 has 32 divisors (see below), whose sum is σ = 23504697216. Its totient is φ = 14691559680.

The previous prime is 18971490563. The next prime is 18971490581. The reversal of 18971490565 is 56509417981.

It is a happy number.

It is not a de Polignac number, because 18971490565 - 2¹ = 18971490563 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 (18971490563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14514642 + ... + 14515948.

It is an arithmetic number, because the mean of its divisors is an integer number (734521788).

Almost surely, 2^18971490565 is an apocalyptic number.

It is an amenable number.

18971490565 is a deficient number, since it is larger than the sum of its proper divisors (4533206651).

18971490565 is a wasteful number, since it uses less digits than its factorization.

18971490565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1909.

The product of its (nonzero) digits is 2721600, while the sum is 55.

The spelling of 18971490565 in words is "eighteen billion, nine hundred seventy-one million, four hundred ninety thousand, five hundred sixty-five".