81976608 has 216 divisors, whose sum is σ = 280284732. Its totient is φ = 22643712.

The previous prime is 81976603. The next prime is 81976613. The reversal of 81976608 is 80667918.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81976603) and next prime (81976613).

It can be written as a sum of positive squares in 2 ways, for example, as 80784144 + 1192464 = 8988^2 + 1092^2 .

It is not an unprimeable number, because it can be changed into a prime (81976603) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 522066 + ... + 522222.

Almost surely, 2^81976608 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 81976608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140142366).

81976608 is an abundant number, since it is smaller than the sum of its proper divisors (198308124).

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

81976608 is a wasteful number, since it uses less digits than its factorization.

81976608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224 (or 206 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The square root of 81976608 is about 9054.0934388817. The cubic root of 81976608 is about 434.4068332208.

The spelling of 81976608 in words is "eighty-one million, nine hundred seventy-six thousand, six hundred eight".