81958373 has 4 divisors (see below), whose sum is σ = 93666720. Its totient is φ = 70250028.

The previous prime is 81958351. The next prime is 81958391. The reversal of 81958373 is 37385918.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81958373 - 2⁸ = 81958117 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81958333) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5854163 + ... + 5854176.

It is an arithmetic number, because the mean of its divisors is an integer number (23416680).

Almost surely, 2^81958373 is an apocalyptic number.

It is an amenable number.

81958373 is a deficient number, since it is larger than the sum of its proper divisors (11708347).

81958373 is a wasteful number, since it uses less digits than its factorization.

81958373 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11708346.

The product of its digits is 181440, while the sum is 44.

The square root of 81958373 is about 9053.0863797934. The cubic root of 81958373 is about 434.3746207957.

The spelling of 81958373 in words is "eighty-one million, nine hundred fifty-eight thousand, three hundred seventy-three".