81793696320 has 280 divisors, whose sum is σ = 332520243264. Its totient is φ = 18695660544.

The previous prime is 81793696319. The next prime is 81793696337. The reversal of 81793696320 is 2369639718.

It is a tau number, because it is divible by the number of its divisors (280).

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 39 ways as a sum of consecutive naturals, for example, 43962 + ... + 406841.

Almost surely, 2^81793696320 is an apocalyptic number.

81793696320 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 81793696320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (166260121632).

81793696320 is an abundant number, since it is smaller than the sum of its proper divisors (250726546944).

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

81793696320 is a wasteful number, since it uses less digits than its factorization.

81793696320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450839 (or 450820 counting only the distinct ones).

The product of its (nonzero) digits is 2939328, while the sum is 54.

The spelling of 81793696320 in words is "eighty-one billion, seven hundred ninety-three million, six hundred ninety-six thousand, three hundred twenty".