83991505 has 8 divisors (see below), whose sum is σ = 108542952. Its totient is φ = 62024448.

The previous prime is 83991473. The next prime is 83991529. The reversal of 83991505 is 50519938.

It can be written as a sum of positive squares in 4 ways, for example, as 18122049 + 65869456 = 4257^2 + 8116^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 83991505 - 2⁵ = 83991473 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 646024 + ... + 646153.

It is an arithmetic number, because the mean of its divisors is an integer number (13567869).

Almost surely, 2^83991505 is an apocalyptic number.

It is an amenable number.

83991505 is a deficient number, since it is larger than the sum of its proper divisors (24551447).

83991505 is a wasteful number, since it uses less digits than its factorization.

83991505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1292195.

The product of its (nonzero) digits is 48600, while the sum is 40.

The square root of 83991505 is about 9164.6879379497. The cubic root of 83991505 is about 437.9371499930.

The spelling of 83991505 in words is "eighty-three million, nine hundred ninety-one thousand, five hundred five".