991361264 has 20 divisors (see below), whose sum is σ = 1952252280. Its totient is φ = 487554240.

The previous prime is 991361257. The next prime is 991361269. The reversal of 991361264 is 462163199.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991361269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 506894 + ... + 508845.

It is an arithmetic number, because the mean of its divisors is an integer number (97612614).

Almost surely, 2^991361264 is an apocalyptic number.

It is an amenable number.

991361264 is a deficient number, since it is larger than the sum of its proper divisors (960891016).

991361264 is a wasteful number, since it uses less digits than its factorization.

991361264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1015808 (or 1015802 counting only the distinct ones).

The product of its digits is 69984, while the sum is 41.

The square root of 991361264 is about 31485.8899191368. The cubic root of 991361264 is about 997.1120893337.

The spelling of 991361264 in words is "nine hundred ninety-one million, three hundred sixty-one thousand, two hundred sixty-four".