81887976 has 64 divisors (see below), whose sum is σ = 228307200. Its totient is φ = 27195264.

The previous prime is 81887941. The next prime is 81887977. The reversal of 81887976 is 67978818.

It is a super-2 number, since 2×81887976² = 13411281226753152, which contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (81887977) 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 15 ways as a sum of consecutive naturals, for example, 78756 + ... + 79788.

It is an arithmetic number, because the mean of its divisors is an integer number (3567300).

Almost surely, 2^81887976 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 81887976, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114153600).

81887976 is an abundant number, since it is smaller than the sum of its proper divisors (146419224).

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

81887976 is a wasteful number, since it uses less digits than its factorization.

81887976 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1415 (or 1405 counting only the distinct ones).

The product of its digits is 1354752, while the sum is 54.

The square root of 81887976 is about 9049.1975334833. The cubic root of 81887976 is about 434.2502184994.

The spelling of 81887976 in words is "eighty-one million, eight hundred eighty-seven thousand, nine hundred seventy-six".