81670042 has 16 divisors (see below), whose sum is σ = 126172800. Its totient is φ = 39630240.

The previous prime is 81670031. The next prime is 81670051. The reversal of 81670042 is 24007618.

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, 4942 + ... + 13702.

It is an arithmetic number, because the mean of its divisors is an integer number (7885800).

Almost surely, 2^81670042 is an apocalyptic number.

81670042 is a deficient number, since it is larger than the sum of its proper divisors (44502758).

81670042 is a wasteful number, since it uses less digits than its factorization.

81670042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8901.

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 81670042 is about 9037.1478907894. The cubic root of 81670042 is about 433.8646431012.

The spelling of 81670042 in words is "eighty-one million, six hundred seventy thousand, forty-two".