991533013 has 4 divisors (see below), whose sum is σ = 1034643168. Its totient is φ = 948422860.

The previous prime is 991532989. The next prime is 991533019. The reversal of 991533013 is 310335199.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 991533013 - 2²⁹ = 454662101 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 991533013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991533019) 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, 21555043 + ... + 21555088.

It is an arithmetic number, because the mean of its divisors is an integer number (258660792).

Almost surely, 2^991533013 is an apocalyptic number.

It is an amenable number.

991533013 is a deficient number, since it is larger than the sum of its proper divisors (43110155).

991533013 is a wasteful number, since it uses less digits than its factorization.

991533013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43110154.

The product of its (nonzero) digits is 10935, while the sum is 34.

The square root of 991533013 is about 31488.6171973302. The cubic root of 991533013 is about 997.1696677772.

The spelling of 991533013 in words is "nine hundred ninety-one million, five hundred thirty-three thousand, thirteen".