81977896 has 128 divisors (see below), whose sum is σ = 214099200. Its totient is φ = 28385280.

The previous prime is 81977887. The next prime is 81977897. The reversal of 81977896 is 69877918.

It is not an unprimeable number, because it can be changed into a prime (81977897) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 232056 + ... + 232408.

It is an arithmetic number, because the mean of its divisors is an integer number (1672650).

Almost surely, 2^81977896 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 81977896, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107049600).

81977896 is an abundant number, since it is smaller than the sum of its proper divisors (132121304).

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

81977896 is a wasteful number, since it uses less digits than its factorization.

81977896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 419 (or 415 counting only the distinct ones).

The product of its digits is 1524096, while the sum is 55.

The square root of 81977896 is about 9054.1645666511. The cubic root of 81977896 is about 434.4091083131.

The spelling of 81977896 in words is "eighty-one million, nine hundred seventy-seven thousand, eight hundred ninety-six".