81996120 has 96 divisors (see below), whose sum is σ = 267883200. Its totient is φ = 21751296.

The previous prime is 81996113. The next prime is 81996121. The reversal of 81996120 is 2169918.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81996121) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 85564 + ... + 86516.

It is an arithmetic number, because the mean of its divisors is an integer number (2790450).

Almost surely, 2^81996120 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 81996120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133941600).

81996120 is an abundant number, since it is smaller than the sum of its proper divisors (185887080).

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

81996120 is a wasteful number, since it uses less digits than its factorization.

81996120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1209 (or 1202 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 81996120 is about 9055.1708984425. The cubic root of 81996120 is about 434.4412961972.

The spelling of 81996120 in words is "eighty-one million, nine hundred ninety-six thousand, one hundred twenty".