81308860 has 24 divisors (see below), whose sum is σ = 173090736. Its totient is φ = 32077440.

The previous prime is 81308849. The next prime is 81308873. The reversal of 81308860 is 6880318.

It is a super-2 number, since 2×81308860² = 13222261428999200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26386 + ... + 29305.

It is an arithmetic number, because the mean of its divisors is an integer number (7212114).

Almost surely, 2^81308860 is an apocalyptic number.

It is an amenable number.

81308860 is an abundant number, since it is smaller than the sum of its proper divisors (91781876).

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

81308860 is a wasteful number, since it uses less digits than its factorization.

81308860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55773 (or 55771 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 34.

The square root of 81308860 is about 9017.1425629187. The cubic root of 81308860 is about 433.2241158018.

The spelling of 81308860 in words is "eighty-one million, three hundred eight thousand, eight hundred sixty".