997999771392 has 864 divisors, whose sum is σ = 3310609306368. Its totient is φ = 297977315328.

The previous prime is 997999771381. The next prime is 997999771411. The reversal of 997999771392 is 293177999799.

997999771392 is a `hidden beast` number, since 9 + 9 + 79 + 9 + 97 + 71 + 392 = 666.

It is a tau number, because it is divible by the number of its divisors (864).

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 6122697903 + ... + 6122698065.

Almost surely, 2^997999771392 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 997999771392, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1655304653184).

997999771392 is an abundant number, since it is smaller than the sum of its proper divisors (2312609534976).

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

997999771392 is a wasteful number, since it uses less digits than its factorization.

997999771392 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 387 (or 361 counting only the distinct ones).

The product of its digits is 1093705578, while the sum is 81.

The spelling of 997999771392 in words is "nine hundred ninety-seven billion, nine hundred ninety-nine million, seven hundred seventy-one thousand, three hundred ninety-two".