81913373 has 8 divisors (see below), whose sum is σ = 86647488. Its totient is φ = 77277024.

The previous prime is 81913343. The next prime is 81913379. The reversal of 81913373 is 37331918.

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 81913373 - 2⁶ = 81913309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81913379) 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, 22715 + ... + 26072.

It is an arithmetic number, because the mean of its divisors is an integer number (10830936).

Almost surely, 2^81913373 is an apocalyptic number.

It is an amenable number.

81913373 is a deficient number, since it is larger than the sum of its proper divisors (4734115).

81913373 is a wasteful number, since it uses less digits than its factorization.

81913373 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48883.

The product of its digits is 13608, while the sum is 35.

The square root of 81913373 is about 9050.6006982962. The cubic root of 81913373 is about 434.2951071118.

The spelling of 81913373 in words is "eighty-one million, nine hundred thirteen thousand, three hundred seventy-three".