81245567 has 12 divisors (see below), whose sum is σ = 93154320. Its totient is φ = 70581888.

The previous prime is 81245561. The next prime is 81245579. The reversal of 81245567 is 76554218.

It is not a de Polignac number, because 81245567 - 2¹⁰ = 81244543 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81245567.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81245561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11267 + ... + 17012.

It is an arithmetic number, because the mean of its divisors is an integer number (7762860).

Almost surely, 2^81245567 is an apocalyptic number.

81245567 is a deficient number, since it is larger than the sum of its proper divisors (11908753).

81245567 is a wasteful number, since it uses less digits than its factorization.

81245567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28322 (or 28309 counting only the distinct ones).

The product of its digits is 67200, while the sum is 38.

The square root of 81245567 is about 9013.6322867088. The cubic root of 81245567 is about 433.1116755263. Note that the first 3 decimals are identical.

The spelling of 81245567 in words is "eighty-one million, two hundred forty-five thousand, five hundred sixty-seven".