81608980 has 12 divisors (see below), whose sum is σ = 171378900. Its totient is φ = 32643584.

The previous prime is 81608953. The next prime is 81608981. The reversal of 81608980 is 8980618.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 65060356 + 16548624 = 8066^2 + 4068^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81608981) 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 3 ways as a sum of consecutive naturals, for example, 2040205 + ... + 2040244.

It is an arithmetic number, because the mean of its divisors is an integer number (14281575).

Almost surely, 2^81608980 is an apocalyptic number.

It is an amenable number.

81608980 is an abundant number, since it is smaller than the sum of its proper divisors (89769920).

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

81608980 is a wasteful number, since it uses less digits than its factorization.

81608980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4080458 (or 4080456 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 40.

The square root of 81608980 is about 9033.7688701892. The cubic root of 81608980 is about 433.7564873748.

The spelling of 81608980 in words is "eighty-one million, six hundred eight thousand, nine hundred eighty".