81607522 has 4 divisors (see below), whose sum is σ = 122411286. Its totient is φ = 40803760.

The previous prime is 81607517. The next prime is 81607549. The reversal of 81607522 is 22570618.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 81522841 + 84681 = 9029^2 + 291^2 .

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20401879 + ... + 20401882.

Almost surely, 2^81607522 is an apocalyptic number.

81607522 is a deficient number, since it is larger than the sum of its proper divisors (40803764).

81607522 is a wasteful number, since it uses less digits than its factorization.

81607522 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40803763.

The product of its (nonzero) digits is 6720, while the sum is 31.

The square root of 81607522 is about 9033.6881726126. The cubic root of 81607522 is about 433.7539042411.

The spelling of 81607522 in words is "eighty-one million, six hundred seven thousand, five hundred twenty-two".