991130223 has 4 divisors (see below), whose sum is σ = 1321506968. Its totient is φ = 660753480.

The previous prime is 991130213. The next prime is 991130227. The reversal of 991130223 is 322031199.

It is a happy number.

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

It is a de Polignac number, because none of the positive numbers 2^k-991130223 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 (991130227) 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, 165188368 + ... + 165188373.

It is an arithmetic number, because the mean of its divisors is an integer number (330376742).

Almost surely, 2^991130223 is an apocalyptic number.

991130223 is a deficient number, since it is larger than the sum of its proper divisors (330376745).

991130223 is a wasteful number, since it uses less digits than its factorization.

991130223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330376744.

The product of its (nonzero) digits is 2916, while the sum is 30.

The square root of 991130223 is about 31482.2207444138. The cubic root of 991130223 is about 997.0346228973.

The spelling of 991130223 in words is "nine hundred ninety-one million, one hundred thirty thousand, two hundred twenty-three".