81609042 has 16 divisors (see below), whose sum is σ = 163426752. Its totient is φ = 27168240.

The previous prime is 81609001. The next prime is 81609067. The reversal of 81609042 is 24090618.

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, 3358 + ... + 13209.

It is an arithmetic number, because the mean of its divisors is an integer number (10214172).

Almost surely, 2^81609042 is an apocalyptic number.

81609042 is an abundant number, since it is smaller than the sum of its proper divisors (81817710).

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

81609042 is a wasteful number, since it uses less digits than its factorization.

81609042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17393.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 81609042 is about 9033.7723017574. The cubic root of 81609042 is about 433.7565972193.

The spelling of 81609042 in words is "eighty-one million, six hundred nine thousand, forty-two".