279664987 has 4 divisors (see below), whose sum is σ = 319617136. Its totient is φ = 239712840.

The previous prime is 279664963. The next prime is 279664999. The reversal of 279664987 is 789466972.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-279664987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (279664087) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19976064 + ... + 19976077.

It is an arithmetic number, because the mean of its divisors is an integer number (79904284).

Almost surely, 2^279664987 is an apocalyptic number.

279664987 is a deficient number, since it is larger than the sum of its proper divisors (39952149).

279664987 is an equidigital number, since it uses as much as digits as its factorization.

279664987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39952148.

The product of its digits is 9144576, while the sum is 58.

The square root of 279664987 is about 16723.1871065297. The cubic root of 279664987 is about 653.9522413042.

The spelling of 279664987 in words is "two hundred seventy-nine million, six hundred sixty-four thousand, nine hundred eighty-seven".