81756714400 has 72 divisors (see below), whose sum is σ = 201419881740. Its totient is φ = 32402626560.

The previous prime is 81756714397. The next prime is 81756714493. The reversal of 81756714400 is 441765718.

It can be written as a sum of positive squares in 6 ways, for example, as 61042596624 + 20714117776 = 247068^2 + 143924^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 381589 + ... + 555988.

Almost surely, 2^81756714400 is an apocalyptic number.

81756714400 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81756714400 is an abundant number, since it is smaller than the sum of its proper divisors (119663167340).

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

81756714400 is a wasteful number, since it uses less digits than its factorization.

81756714400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 937706 (or 937693 counting only the distinct ones).

The product of its (nonzero) digits is 188160, while the sum is 43.

The spelling of 81756714400 in words is "eighty-one billion, seven hundred fifty-six million, seven hundred fourteen thousand, four hundred".