81924753456 has 480 divisors, whose sum is σ = 295684408320. Its totient is φ = 21526331904.

The previous prime is 81924753433. The next prime is 81924753461. The reversal of 81924753456 is 65435742918.

It is a happy number.

81924753456 is a `hidden beast` number, since 8 + 1 + 92 + 475 + 34 + 56 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 127409871 + ... + 127410513.

It is an arithmetic number, because the mean of its divisors is an integer number (616009184).

Almost surely, 2^81924753456 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 81924753456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (147842204160).

81924753456 is an abundant number, since it is smaller than the sum of its proper divisors (213759654864).

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

81924753456 is a wasteful number, since it uses less digits than its factorization.

81924753456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1150 (or 1131 counting only the distinct ones).

The product of its digits is 7257600, while the sum is 54.

The spelling of 81924753456 in words is "eighty-one billion, nine hundred twenty-four million, seven hundred fifty-three thousand, four hundred fifty-six".