81396179 has 4 divisors (see below), whose sum is σ = 81914784. Its totient is φ = 80877576.

The previous prime is 81396109. The next prime is 81396199. The reversal of 81396179 is 97169318.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97169318 = 2 ⋅48584659.

It is a cyclic number.

It is not a de Polignac number, because 81396179 - 2¹² = 81392083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81396109) 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, 259067 + ... + 259380.

It is an arithmetic number, because the mean of its divisors is an integer number (20478696).

Almost surely, 2^81396179 is an apocalyptic number.

81396179 is a deficient number, since it is larger than the sum of its proper divisors (518605).

81396179 is a wasteful number, since it uses less digits than its factorization.

81396179 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 518604.

The product of its digits is 81648, while the sum is 44.

The square root of 81396179 is about 9021.9830968585. The cubic root of 81396179 is about 433.3791426259.

The spelling of 81396179 in words is "eighty-one million, three hundred ninety-six thousand, one hundred seventy-nine".