660279899621 has 2 divisors, whose sum is σ = 660279899622. Its totient is φ = 660279899620.

The previous prime is 660279899611. The next prime is 660279899623. The reversal of 660279899621 is 126998972066.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 603690150625 + 56589748996 = 776975^2 + 237886^2 .

It is a cyclic number.

It is not a de Polignac number, because 660279899621 - 2⁶ = 660279899557 is a prime.

Together with 660279899623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (660279899623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330139949810 + 330139949811.

It is an arithmetic number, because the mean of its divisors is an integer number (330139949811).

Almost surely, 2^660279899621 is an apocalyptic number.

It is an amenable number.

660279899621 is a deficient number, since it is larger than the sum of its proper divisors (1).

660279899621 is an equidigital number, since it uses as much as digits as its factorization.

660279899621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 35271936, while the sum is 65.

The spelling of 660279899621 in words is "six hundred sixty billion, two hundred seventy-nine million, eight hundred ninety-nine thousand, six hundred twenty-one".