81319086 has 32 divisors (see below), whose sum is σ = 181015200. Its totient is φ = 27060480.

The previous prime is 81319079. The next prime is 81319093. The reversal of 81319086 is 68091318.

It is an interprime number because it is at equal distance from previous prime (81319079) and next prime (81319093).

It is a super-2 number, since 2×81319086² = 13225587495750792, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81319086.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49356 + ... + 50976.

It is an arithmetic number, because the mean of its divisors is an integer number (5656725).

Almost surely, 2^81319086 is an apocalyptic number.

81319086 is an abundant number, since it is smaller than the sum of its proper divisors (99696114).

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

81319086 is a wasteful number, since it uses less digits than its factorization.

81319086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2561 (or 2555 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 81319086 is about 9017.7095761618. The cubic root of 81319086 is about 433.2422768571.

The spelling of 81319086 in words is "eighty-one million, three hundred nineteen thousand, eighty-six".