661344331 has 2 divisors, whose sum is σ = 661344332. Its totient is φ = 661344330.

The previous prime is 661344317. The next prime is 661344349. The reversal of 661344331 is 133443166.

It is a happy number.

661344331 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 661344331 - 2⁹ = 661343819 is a prime.

It is a super-2 number, since 2×661344331² = 874752648291675122, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 661344293 and 661344302.

It is not a weakly prime, because it can be changed into another prime (661344361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330672165 + 330672166.

It is an arithmetic number, because the mean of its divisors is an integer number (330672166).

Almost surely, 2^661344331 is an apocalyptic number.

661344331 is a deficient number, since it is larger than the sum of its proper divisors (1).

661344331 is an equidigital number, since it uses as much as digits as its factorization.

661344331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15552, while the sum is 31.

The square root of 661344331 is about 25716.6158543460. The cubic root of 661344331 is about 871.2495063832.

Adding to 661344331 its reverse (133443166), we get a palindrome (794787497).

The spelling of 661344331 in words is "six hundred sixty-one million, three hundred forty-four thousand, three hundred thirty-one".