81735515616 has 96 divisors (see below), whose sum is σ = 222032434176. Its totient is φ = 26300160000.

The previous prime is 81735515591. The next prime is 81735515627. The reversal of 81735515616 is 61651553718.

It is a tau number, because it is divible by the number of its divisors (96).

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

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 15 ways as a sum of consecutive naturals, for example, 1159131 + ... + 1227621.

It is an arithmetic number, because the mean of its divisors is an integer number (2312837856).

Almost surely, 2^81735515616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81735515616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111016217088).

81735515616 is an abundant number, since it is smaller than the sum of its proper divisors (140296918560).

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

81735515616 is a wasteful number, since it uses less digits than its factorization.

81735515616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68936 (or 68928 counting only the distinct ones).

The product of its digits is 756000, while the sum is 48.

The spelling of 81735515616 in words is "eighty-one billion, seven hundred thirty-five million, five hundred fifteen thousand, six hundred sixteen".