291117983 has 4 divisors (see below), whose sum is σ = 313511688. Its totient is φ = 268724280.

The previous prime is 291117949. The next prime is 291118027. The reversal of 291117983 is 389711192.

It is a happy number.

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 291117983 - 2¹² = 291113887 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 291117983.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (291117913) 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, 11196833 + ... + 11196858.

It is an arithmetic number, because the mean of its divisors is an integer number (78377922).

Almost surely, 2^291117983 is an apocalyptic number.

291117983 is a deficient number, since it is larger than the sum of its proper divisors (22393705).

291117983 is a wasteful number, since it uses less digits than its factorization.

291117983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22393704.

The product of its digits is 27216, while the sum is 41.

The square root of 291117983 is about 17062.1799017593. The cubic root of 291117983 is about 662.7600843310.

The spelling of 291117983 in words is "two hundred ninety-one million, one hundred seventeen thousand, nine hundred eighty-three".