81758751600 has 240 divisors, whose sum is σ = 265660746624. Its totient is φ = 21490560000.

The previous prime is 81758751587. The next prime is 81758751617. The reversal of 81758751600 is 615785718.

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a self number, because there is not a number n which added to its sum of digits gives 81758751600.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 69819015 + ... + 69820185.

Almost surely, 2^81758751600 is an apocalyptic number.

81758751600 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81758751600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132830373312).

81758751600 is an abundant number, since it is smaller than the sum of its proper divisors (183901995024).

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

81758751600 is a wasteful number, since it uses less digits than its factorization.

81758751600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1976 (or 1965 counting only the distinct ones).

The product of its (nonzero) digits is 470400, while the sum is 48.

The spelling of 81758751600 in words is "eighty-one billion, seven hundred fifty-eight million, seven hundred fifty-one thousand, six hundred".