997888321 has 8 divisors (see below), whose sum is σ = 1056987360. Its totient is φ = 938833728.

The previous prime is 997888279. The next prime is 997888343. The reversal of 997888321 is 123888799.

997888321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 997888321 - 2⁷ = 997888193 is a prime.

It is a super-2 number, since 2×997888321² = 1991562202376398082, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (997888391) 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, 42570 + ... + 61708.

It is an arithmetic number, because the mean of its divisors is an integer number (132123420).

Almost surely, 2^997888321 is an apocalyptic number.

It is an amenable number.

997888321 is a deficient number, since it is larger than the sum of its proper divisors (59099039).

997888321 is a wasteful number, since it uses less digits than its factorization.

997888321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22223.

The product of its digits is 1741824, while the sum is 55.

The square root of 997888321 is about 31589.3703799237. The cubic root of 997888321 is about 999.2956109526.

The spelling of 997888321 in words is "nine hundred ninety-seven million, eight hundred eighty-eight thousand, three hundred twenty-one".