81519078159 has 32 divisors (see below), whose sum is σ = 124849771200. Its totient is φ = 52534033920.

The previous prime is 81519078149. The next prime is 81519078163. The reversal of 81519078159 is 95187091518.

It is a happy number.

81519078159 is a `hidden beast` number, since 8 + 1 + 519 + 0 + 78 + 1 + 59 = 666.

It is not a de Polignac number, because 81519078159 - 2⁵ = 81519078127 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81519078149) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 217134 + ... + 458459.

It is an arithmetic number, because the mean of its divisors is an integer number (3901555350).

Almost surely, 2^81519078159 is an apocalyptic number.

81519078159 is a deficient number, since it is larger than the sum of its proper divisors (43330693041).

81519078159 is a wasteful number, since it uses less digits than its factorization.

81519078159 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 675752 (or 675746 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 54.

The spelling of 81519078159 in words is "eighty-one billion, five hundred nineteen million, seventy-eight thousand, one hundred fifty-nine".