81607569 has 8 divisors (see below), whose sum is σ = 110594112. Its totient is φ = 53513040.

The previous prime is 81607549. The next prime is 81607579. The reversal of 81607569 is 96570618.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81607569 - 2¹¹ = 81605521 is a prime.

It is a super-2 number, since 2×81607569² = 13319590636179522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81607569.

It is not an unprimeable number, because it can be changed into a prime (81607549) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 222789 + ... + 223154.

It is an arithmetic number, because the mean of its divisors is an integer number (13824264).

Almost surely, 2^81607569 is an apocalyptic number.

It is an amenable number.

81607569 is a deficient number, since it is larger than the sum of its proper divisors (28986543).

81607569 is a wasteful number, since it uses less digits than its factorization.

81607569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446007.

The product of its (nonzero) digits is 90720, while the sum is 42.

The square root of 81607569 is about 9033.6907739860. The cubic root of 81607569 is about 433.7539875113.

The spelling of 81607569 in words is "eighty-one million, six hundred seven thousand, five hundred sixty-nine".