997821312 has 64 divisors (see below), whose sum is σ = 2654415360. Its totient is φ = 332111360.

The previous prime is 997821283. The next prime is 997821329. The reversal of 997821312 is 213128799.

997821312 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 329887 + ... + 332897.

It is an arithmetic number, because the mean of its divisors is an integer number (41475240).

Almost surely, 2^997821312 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 997821312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1327207680).

997821312 is an abundant number, since it is smaller than the sum of its proper divisors (1656594048).

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

997821312 is a wasteful number, since it uses less digits than its factorization.

997821312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3891 (or 3879 counting only the distinct ones).

The product of its digits is 54432, while the sum is 42.

The square root of 997821312 is about 31588.3097363566. The cubic root of 997821312 is about 999.2732426183.

The spelling of 997821312 in words is "nine hundred ninety-seven million, eight hundred twenty-one thousand, three hundred twelve".