81612365 has 16 divisors (see below), whose sum is σ = 100025280. Its totient is φ = 63909120.

The previous prime is 81612347. The next prime is 81612373. The reversal of 81612365 is 56321618.

It is a happy number.

It is not a de Polignac number, because 81612365 - 2⁸ = 81612109 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59285 + ... + 60645.

It is an arithmetic number, because the mean of its divisors is an integer number (6251580).

Almost surely, 2^81612365 is an apocalyptic number.

It is an amenable number.

81612365 is a deficient number, since it is larger than the sum of its proper divisors (18412915).

81612365 is a wasteful number, since it uses less digits than its factorization.

81612365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1612.

The product of its digits is 8640, while the sum is 32.

The square root of 81612365 is about 9033.9562208370. The cubic root of 81612365 is about 433.7624844494.

The spelling of 81612365 in words is "eighty-one million, six hundred twelve thousand, three hundred sixty-five".