81136499 has 8 divisors (see below), whose sum is σ = 83926752. Its totient is φ = 78384960.

The previous prime is 81136493. The next prime is 81136511. The reversal of 81136499 is 99463118.

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

It is a cyclic number.

It is not a de Polignac number, because 81136499 - 2⁴ = 81136483 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81136493) 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, 5384 + ... + 13829.

It is an arithmetic number, because the mean of its divisors is an integer number (10490844).

Almost surely, 2^81136499 is an apocalyptic number.

81136499 is a deficient number, since it is larger than the sum of its proper divisors (2790253).

81136499 is a wasteful number, since it uses less digits than its factorization.

81136499 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19357.

The product of its digits is 46656, while the sum is 41.

The square root of 81136499 is about 9007.5800856834. The cubic root of 81136499 is about 432.9177786766.

The spelling of 81136499 in words is "eighty-one million, one hundred thirty-six thousand, four hundred ninety-nine".