15491994865 has 8 divisors (see below), whose sum is σ = 18596257128. Its totient is φ = 12389687040.

The previous prime is 15491994841. The next prime is 15491994877. The reversal of 15491994865 is 56849919451.

It can be written as a sum of positive squares in 4 ways, for example, as 2034370816 + 13457624049 = 45104^2 + 116007^2 .

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

It is not a de Polignac number, because 15491994865 - 2²⁷ = 15357777137 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 471112 + ... + 502921.

It is an arithmetic number, because the mean of its divisors is an integer number (2324532141).

Almost surely, 2^15491994865 is an apocalyptic number.

It is an amenable number.

15491994865 is a deficient number, since it is larger than the sum of its proper divisors (3104262263).

15491994865 is an equidigital number, since it uses as much as digits as its factorization.

15491994865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 977219.

The product of its digits is 13996800, while the sum is 61.

The spelling of 15491994865 in words is "fifteen billion, four hundred ninety-one million, nine hundred ninety-four thousand, eight hundred sixty-five".