18378172015 has 24 divisors (see below), whose sum is σ = 25664725152. Its totient is φ = 12597117120.

The previous prime is 18378171991. The next prime is 18378172037. The reversal of 18378172015 is 51027187381.

It is not a de Polignac number, because 18378172015 - 2³³ = 9788237423 is a prime.

It is a super-2 number, since 2×18378172015² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 657862 + ... + 685228.

It is an arithmetic number, because the mean of its divisors is an integer number (1069363548).

Almost surely, 2^18378172015 is an apocalyptic number.

18378172015 is a deficient number, since it is larger than the sum of its proper divisors (7286553137).

18378172015 is a wasteful number, since it uses less digits than its factorization.

18378172015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30127 (or 30120 counting only the distinct ones).

The product of its (nonzero) digits is 94080, while the sum is 43.

The spelling of 18378172015 in words is "eighteen billion, three hundred seventy-eight million, one hundred seventy-two thousand, fifteen".