260640389 has 2 divisors, whose sum is σ = 260640390. Its totient is φ = 260640388.

The previous prime is 260640377. The next prime is 260640397. The reversal of 260640389 is 983046062.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 135536164 + 125104225 = 11642^2 + 11185^2 .

It is a cyclic number.

It is not a de Polignac number, because 260640389 - 2²⁴ = 243863173 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (260640349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130320194 + 130320195.

It is an arithmetic number, because the mean of its divisors is an integer number (130320195).

Almost surely, 2^260640389 is an apocalyptic number.

It is an amenable number.

260640389 is a deficient number, since it is larger than the sum of its proper divisors (1).

260640389 is an equidigital number, since it uses as much as digits as its factorization.

260640389 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 62208, while the sum is 38.

The square root of 260640389 is about 16144.3609040432. The cubic root of 260640389 is about 638.7740112220.

The spelling of 260640389 in words is "two hundred sixty million, six hundred forty thousand, three hundred eighty-nine".