663331 has 2 divisors, whose sum is σ = 663332. Its totient is φ = 663330.

The previous prime is 663319. The next prime is 663349. The reversal of 663331 is 133366.

It is a happy number.

663331 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 663331 - 2⁷ = 663203 is a prime.

It is a super-2 number, since 2×663331² = 880016031122, which contains 22 as substring.

663331 is a lucky number.

It is a nialpdrome in base 10.

It is not a weakly prime, because it can be changed into another prime (663301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 331665 + 331666.

It is an arithmetic number, because the mean of its divisors is an integer number (331666).

2⁶⁶³³³¹ is an apocalyptic number.

663331 is a deficient number, since it is larger than the sum of its proper divisors (1).

663331 is an equidigital number, since it uses as much as digits as its factorization.

663331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 972, while the sum is 22.

The square root of 663331 is about 814.4513490688. The cubic root of 663331 is about 87.2121041330.

Adding to 663331 its reverse (133366), we get a palindrome (796697).

It can be divided in two parts, 663 and 331, that multiplied together give a triangular number (219453 = T₆₆₂).

The spelling of 663331 in words is "six hundred sixty-three thousand, three hundred thirty-one".