81408305 has 16 divisors (see below), whose sum is σ = 107179200. Its totient is φ = 58868160.

The previous prime is 81408253. The next prime is 81408311. The reversal of 81408305 is 50380418.

It is not a de Polignac number, because 81408305 - 2⁸ = 81408049 is a prime.

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, 5711 + ... + 13979.

It is an arithmetic number, because the mean of its divisors is an integer number (6698700).

Almost surely, 2^81408305 is an apocalyptic number.

It is an amenable number.

81408305 is a deficient number, since it is larger than the sum of its proper divisors (25770895).

81408305 is a wasteful number, since it uses less digits than its factorization.

81408305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8464.

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 81408305 is about 9022.6550970321. The cubic root of 81408305 is about 433.4006624508.

The spelling of 81408305 in words is "eighty-one million, four hundred eight thousand, three hundred five".