81886379 has 4 divisors (see below), whose sum is σ = 82020576. Its totient is φ = 81752184.

The previous prime is 81886369. The next prime is 81886403. The reversal of 81886379 is 97368818.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81886379 - 2²⁰ = 80837803 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81886309) 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, 66179 + ... + 67404.

It is an arithmetic number, because the mean of its divisors is an integer number (20505144).

Almost surely, 2^81886379 is an apocalyptic number.

81886379 is a deficient number, since it is larger than the sum of its proper divisors (134197).

81886379 is a wasteful number, since it uses less digits than its factorization.

81886379 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134196.

The product of its digits is 580608, while the sum is 50.

The square root of 81886379 is about 9049.1092931846. The cubic root of 81886379 is about 434.2473955286.

The spelling of 81886379 in words is "eighty-one million, eight hundred eighty-six thousand, three hundred seventy-nine".