81608570 has 16 divisors (see below), whose sum is σ = 147667968. Its totient is φ = 32471760.

The previous prime is 81608567. The next prime is 81608599. The reversal of 81608570 is 7580618.

It is a happy number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81608570.

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, 19454 + ... + 23273.

It is an arithmetic number, because the mean of its divisors is an integer number (9229248).

Almost surely, 2^81608570 is an apocalyptic number.

81608570 is a deficient number, since it is larger than the sum of its proper divisors (66059398).

81608570 is a wasteful number, since it uses less digits than its factorization.

81608570 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42925.

The product of its (nonzero) digits is 13440, while the sum is 35.

The square root of 81608570 is about 9033.7461775279. The cubic root of 81608570 is about 433.7557609823.

The spelling of 81608570 in words is "eighty-one million, six hundred eight thousand, five hundred seventy".