82991399 has 8 divisors (see below), whose sum is σ = 88015248. Its totient is φ = 77983360.

The previous prime is 82991369. The next prime is 82991413. The reversal of 82991399 is 99319928.

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-82991399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82991369) 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, 7904 + ... + 15114.

It is an arithmetic number, because the mean of its divisors is an integer number (11001906).

Almost surely, 2^82991399 is an apocalyptic number.

82991399 is a deficient number, since it is larger than the sum of its proper divisors (5023849).

82991399 is a wasteful number, since it uses less digits than its factorization.

82991399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7905.

The product of its digits is 314928, while the sum is 50.

The square root of 82991399 is about 9109.9615257146. The cubic root of 82991399 is about 436.1919990869.

The spelling of 82991399 in words is "eighty-two million, nine hundred ninety-one thousand, three hundred ninety-nine".