81495812 has 12 divisors (see below), whose sum is σ = 143926860. Its totient is φ = 40373856.

The previous prime is 81495809. The next prime is 81495863. The reversal of 81495812 is 21859418.

It can be written as a sum of positive squares in 2 ways, for example, as 70829056 + 10666756 = 8416^2 + 3266^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93023 + ... + 93894.

It is an arithmetic number, because the mean of its divisors is an integer number (11993905).

Almost surely, 2^81495812 is an apocalyptic number.

It is an amenable number.

81495812 is a deficient number, since it is larger than the sum of its proper divisors (62431048).

81495812 is a wasteful number, since it uses less digits than its factorization.

81495812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187030 (or 187028 counting only the distinct ones).

The product of its digits is 23040, while the sum is 38.

The square root of 81495812 is about 9027.5030877868. The cubic root of 81495812 is about 433.5558964528. Note that the first 3 decimals are identical.

The spelling of 81495812 in words is "eighty-one million, four hundred ninety-five thousand, eight hundred twelve".