81893133 has 32 divisors (see below), whose sum is σ = 144691200. Its totient is φ = 44759088.

The previous prime is 81893107. The next prime is 81893143. The reversal of 81893133 is 33139818.

It is not a de Polignac number, because 81893133 - 2⁶ = 81893069 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81893143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5073 + ... + 13766.

It is an arithmetic number, because the mean of its divisors is an integer number (4521600).

Almost surely, 2^81893133 is an apocalyptic number.

It is an amenable number.

81893133 is a deficient number, since it is larger than the sum of its proper divisors (62798067).

81893133 is a wasteful number, since it uses less digits than its factorization.

81893133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18878 (or 18872 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 81893133 is about 9049.4824713903. The cubic root of 81893133 is about 434.2593341290.

The spelling of 81893133 in words is "eighty-one million, eight hundred ninety-three thousand, one hundred thirty-three".