81519270816 has 48 divisors (see below), whose sum is σ = 216696816000. Its totient is φ = 26829124608.

The previous prime is 81519270809. The next prime is 81519270817. The reversal of 81519270816 is 61807291518.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is not an unprimeable number, because it can be changed into a prime (81519270817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5366841 + ... + 5382008.

It is an arithmetic number, because the mean of its divisors is an integer number (4514517000).

Almost surely, 2^81519270816 is an apocalyptic number.

It is an amenable number.

81519270816 is an abundant number, since it is smaller than the sum of its proper divisors (135177545184).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81519270816 is a wasteful number, since it uses less digits than its factorization.

81519270816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10748941 (or 10748933 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 48.

The spelling of 81519270816 in words is "eighty-one billion, five hundred nineteen million, two hundred seventy thousand, eight hundred sixteen".