997991264 has 48 divisors (see below), whose sum is σ = 2099160000. Its totient is φ = 465657984.

The previous prime is 997991263. The next prime is 997991287. The reversal of 997991264 is 462199799.

997991264 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (997991263) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28487 + ... + 52985.

It is an arithmetic number, because the mean of its divisors is an integer number (43732500).

Almost surely, 2^997991264 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 997991264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1049580000).

997991264 is an abundant number, since it is smaller than the sum of its proper divisors (1101168736).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

997991264 is a wasteful number, since it uses less digits than its factorization.

997991264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24595 (or 24587 counting only the distinct ones).

The product of its digits is 2204496, while the sum is 56.

The square root of 997991264 is about 31590.9997309360. Note that the first 3 decimals coincide. The cubic root of 997991264 is about 999.3299724967.

The spelling of 997991264 in words is "nine hundred ninety-seven million, nine hundred ninety-one thousand, two hundred sixty-four".