81136545 has 32 divisors (see below), whose sum is σ = 148780800. Its totient is φ = 36986880.

The previous prime is 81136541. The next prime is 81136547. The reversal of 81136545 is 54563118.

It is not a de Polignac number, because 81136545 - 2² = 81136541 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81136541) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 46285 + ... + 48005.

It is an arithmetic number, because the mean of its divisors is an integer number (4649400).

Almost surely, 2^81136545 is an apocalyptic number.

It is an amenable number.

81136545 is a deficient number, since it is larger than the sum of its proper divisors (67644255).

81136545 is a wasteful number, since it uses less digits than its factorization.

81136545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2185.

The product of its digits is 14400, while the sum is 33.

The square root of 81136545 is about 9007.5826390880. The cubic root of 81136545 is about 432.9178604902.

The spelling of 81136545 in words is "eighty-one million, one hundred thirty-six thousand, five hundred forty-five".