991936239 has 16 divisors (see below), whose sum is σ = 1528508160. Its totient is φ = 560450880.

The previous prime is 991936223. The next prime is 991936241. The reversal of 991936239 is 932639199.

It is a happy number.

It is not a de Polignac number, because 991936239 - 2⁴ = 991936223 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 991936191 and 991936200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991936639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 263497 + ... + 267234.

It is an arithmetic number, because the mean of its divisors is an integer number (95531760).

Almost surely, 2^991936239 is an apocalyptic number.

991936239 is a deficient number, since it is larger than the sum of its proper divisors (536571921).

991936239 is a wasteful number, since it uses less digits than its factorization.

991936239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 530830.

The product of its digits is 708588, while the sum is 51.

The square root of 991936239 is about 31495.0192728946. The cubic root of 991936239 is about 997.3048222093.

The spelling of 991936239 in words is "nine hundred ninety-one million, nine hundred thirty-six thousand, two hundred thirty-nine".