81692997120 has 800 divisors, whose sum is σ = 349079943168. Its totient is φ = 17853530112.

The previous prime is 81692997073. The next prime is 81692997131. The reversal of 81692997120 is 2179929618.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 33383737 + ... + 33386183.

Almost surely, 2^81692997120 is an apocalyptic number.

81692997120 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 81692997120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (174539971584).

81692997120 is an abundant number, since it is smaller than the sum of its proper divisors (267386946048).

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

81692997120 is a wasteful number, since it uses less digits than its factorization.

81692997120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2512 (or 2487 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 54.

The spelling of 81692997120 in words is "eighty-one billion, six hundred ninety-two million, nine hundred ninety-seven thousand, one hundred twenty".