81873339 has 4 divisors (see below), whose sum is σ = 109164456. Its totient is φ = 54582224.

The previous prime is 81873331. The next prime is 81873349. The reversal of 81873339 is 93337818.

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 81873339 - 2³ = 81873331 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81873339.

It is not an unprimeable number, because it can be changed into a prime (81873331) 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, 13645554 + ... + 13645559.

It is an arithmetic number, because the mean of its divisors is an integer number (27291114).

Almost surely, 2^81873339 is an apocalyptic number.

81873339 is a deficient number, since it is larger than the sum of its proper divisors (27291117).

81873339 is a wasteful number, since it uses less digits than its factorization.

81873339 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27291116.

The product of its digits is 108864, while the sum is 42.

The square root of 81873339 is about 9048.3887515955. The cubic root of 81873339 is about 434.2243437231.

The spelling of 81873339 in words is "eighty-one million, eight hundred seventy-three thousand, three hundred thirty-nine".