279956921 has 2 divisors, whose sum is σ = 279956922. Its totient is φ = 279956920.

The previous prime is 279956899. The next prime is 279956933. The reversal of 279956921 is 129659972.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 213306025 + 66650896 = 14605^2 + 8164^2 .

It is a cyclic number.

It is not a de Polignac number, because 279956921 - 2¹⁸ = 279694777 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 279956921.

It is not a weakly prime, because it can be changed into another prime (279956021) 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, 139978460 + 139978461.

It is an arithmetic number, because the mean of its divisors is an integer number (139978461).

Almost surely, 2^279956921 is an apocalyptic number.

It is an amenable number.

279956921 is a deficient number, since it is larger than the sum of its proper divisors (1).

279956921 is an equidigital number, since it uses as much as digits as its factorization.

279956921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 612360, while the sum is 50.

The square root of 279956921 is about 16731.9132498349. The cubic root of 279956921 is about 654.1797093013.

The spelling of 279956921 in words is "two hundred seventy-nine million, nine hundred fifty-six thousand, nine hundred twenty-one".