331997999 has 4 divisors (see below), whose sum is σ = 332834664. Its totient is φ = 331161336.

The previous prime is 331997971. The next prime is 331998011. The reversal of 331997999 is 999799133.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-331997999 is a prime.

It is a super-2 number, since 2×331997999² = 220445342680008002, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (331997959) 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, 417737 + ... + 418530.

It is an arithmetic number, because the mean of its divisors is an integer number (83208666).

Almost surely, 2^331997999 is an apocalyptic number.

331997999 is a deficient number, since it is larger than the sum of its proper divisors (836665).

331997999 is an equidigital number, since it uses as much as digits as its factorization.

331997999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 836664.

The product of its digits is 3720087, while the sum is 59.

The square root of 331997999 is about 18220.8122486348. The cubic root of 331997999 is about 692.4341661318.

The spelling of 331997999 in words is "three hundred thirty-one million, nine hundred ninety-seven thousand, nine hundred ninety-nine".