991311203 has 4 divisors (see below), whose sum is σ = 991924368. Its totient is φ = 990698040.

The previous prime is 991311199. The next prime is 991311227. The reversal of 991311203 is 302113199.

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 991311203 - 2² = 991311199 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991311253) 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, 304151 + ... + 307392.

It is an arithmetic number, because the mean of its divisors is an integer number (247981092).

Almost surely, 2^991311203 is an apocalyptic number.

991311203 is a deficient number, since it is larger than the sum of its proper divisors (613165).

991311203 is a wasteful number, since it uses less digits than its factorization.

991311203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 613164.

The product of its (nonzero) digits is 1458, while the sum is 29.

The square root of 991311203 is about 31485.0949339525. The cubic root of 991311203 is about 997.0953052510.

The spelling of 991311203 in words is "nine hundred ninety-one million, three hundred eleven thousand, two hundred three".