331405331 has 2 divisors, whose sum is σ = 331405332. Its totient is φ = 331405330.

The previous prime is 331405313. The next prime is 331405379. The reversal of 331405331 is 133504133.

It is a happy number.

Together with previous prime (331405313) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-331405331 is a prime.

It is a super-2 number, since 2×331405331² = 219658986830439122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 331405297 and 331405306.

It is not a weakly prime, because it can be changed into another prime (331405381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165702665 + 165702666.

It is an arithmetic number, because the mean of its divisors is an integer number (165702666).

Almost surely, 2^331405331 is an apocalyptic number.

331405331 is a deficient number, since it is larger than the sum of its proper divisors (1).

331405331 is an equidigital number, since it uses as much as digits as its factorization.

331405331 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1620, while the sum is 23.

The square root of 331405331 is about 18204.5414938141. The cubic root of 331405331 is about 692.0218865242.

Adding to 331405331 its reverse (133504133), we get a palindrome (464909464).

The spelling of 331405331 in words is "three hundred thirty-one million, four hundred five thousand, three hundred thirty-one".