81137133 has 40 divisors (see below), whose sum is σ = 151124160. Its totient is φ = 42145920.

The previous prime is 81137113. The next prime is 81137143. The reversal of 81137133 is 33173118.

It is not a de Polignac number, because 81137133 - 2¹³ = 81128941 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 81137097 and 81137106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81137113) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 268 + ... + 12741.

It is an arithmetic number, because the mean of its divisors is an integer number (3778104).

Almost surely, 2^81137133 is an apocalyptic number.

It is an amenable number.

81137133 is a deficient number, since it is larger than the sum of its proper divisors (69987027).

81137133 is a wasteful number, since it uses less digits than its factorization.

81137133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13039 (or 13030 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 81137133 is about 9007.6152781966. The cubic root of 81137133 is about 432.9189062791.

The spelling of 81137133 in words is "eighty-one million, one hundred thirty-seven thousand, one hundred thirty-three".