81958123 has 8 divisors (see below), whose sum is σ = 88654608. Its totient is φ = 75317664.

The previous prime is 81958117. The next prime is 81958127. The reversal of 81958123 is 32185918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81958123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81958127) 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, 10936 + ... + 16837.

It is an arithmetic number, because the mean of its divisors is an integer number (11081826).

Almost surely, 2^81958123 is an apocalyptic number.

81958123 is a deficient number, since it is larger than the sum of its proper divisors (6696485).

81958123 is a wasteful number, since it uses less digits than its factorization.

81958123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28013.

The product of its digits is 17280, while the sum is 37.

The square root of 81958123 is about 9053.0725723370. The cubic root of 81958123 is about 434.3741791334.

The spelling of 81958123 in words is "eighty-one million, nine hundred fifty-eight thousand, one hundred twenty-three".