81579356 has 6 divisors (see below), whose sum is σ = 142763880. Its totient is φ = 40789676.

The previous prime is 81579319. The next prime is 81579389. The reversal of 81579356 is 65397518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10197416 + ... + 10197423.

It is an arithmetic number, because the mean of its divisors is an integer number (23793980).

Almost surely, 2^81579356 is an apocalyptic number.

It is an amenable number.

81579356 is a deficient number, since it is larger than the sum of its proper divisors (61184524).

81579356 is a wasteful number, since it uses less digits than its factorization.

81579356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20394843 (or 20394841 counting only the distinct ones).

The product of its digits is 226800, while the sum is 44.

The square root of 81579356 is about 9032.1290956230. The cubic root of 81579356 is about 433.7039965938.

The spelling of 81579356 in words is "eighty-one million, five hundred seventy-nine thousand, three hundred fifty-six".