991133610307 has 4 divisors (see below), whose sum is σ = 991135642480. Its totient is φ = 991131578136.

The previous prime is 991133610289. The next prime is 991133610319. The reversal of 991133610307 is 703016331199.

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

It is a 3-Lehmer number, since φ(991133610307) divides (991133610307-1)³.

It is a cyclic number.

It is not a de Polignac number, because 991133610307 - 2¹⁹ = 991133086019 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (991133610367) 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, 203218 + ... + 1422520.

It is an arithmetic number, because the mean of its divisors is an integer number (247783910620).

Almost surely, 2^991133610307 is an apocalyptic number.

991133610307 is the 812869-th pentagonal number.

991133610307 is a deficient number, since it is larger than the sum of its proper divisors (2032173).

991133610307 is a wasteful number, since it uses less digits than its factorization.

991133610307 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2032172.

The product of its (nonzero) digits is 91854, while the sum is 43.

The spelling of 991133610307 in words is "nine hundred ninety-one billion, one hundred thirty-three million, six hundred ten thousand, three hundred seven".