661894339 has 2 divisors, whose sum is σ = 661894340. Its totient is φ = 661894338.

The previous prime is 661894319. The next prime is 661894351. The reversal of 661894339 is 933498166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661894339 - 2⁵ = 661894307 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 661894292 and 661894301.

It is not a weakly prime, because it can be changed into another prime (661894319) 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 as a sum of consecutive naturals, namely, 330947169 + 330947170.

It is an arithmetic number, because the mean of its divisors is an integer number (330947170).

Almost surely, 2^661894339 is an apocalyptic number.

661894339 is a deficient number, since it is larger than the sum of its proper divisors (1).

661894339 is an equidigital number, since it uses as much as digits as its factorization.

661894339 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 839808, while the sum is 49.

The square root of 661894339 is about 25727.3072629065. The cubic root of 661894339 is about 871.4909647767.

The spelling of 661894339 in words is "six hundred sixty-one million, eight hundred ninety-four thousand, three hundred thirty-nine".