279998921 has 4 divisors (see below), whose sum is σ = 280082052. Its totient is φ = 279915792.

The previous prime is 279998909. The next prime is 279998951. The reversal of 279998921 is 129899972.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 115261696 + 164737225 = 10736^2 + 12835^2 .

It is a cyclic number.

It is not a de Polignac number, because 279998921 - 2²⁶ = 212890057 is a prime.

It is a super-2 number, since 2×279998921² = 156798791522328482, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (279998951) 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, 36290 + ... + 43323.

It is an arithmetic number, because the mean of its divisors is an integer number (70020513).

Almost surely, 2^279998921 is an apocalyptic number.

It is an amenable number.

279998921 is a deficient number, since it is larger than the sum of its proper divisors (83131).

279998921 is an equidigital number, since it uses as much as digits as its factorization.

279998921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83130.

The product of its digits is 1469664, while the sum is 56.

The square root of 279998921 is about 16733.1682893587. The cubic root of 279998921 is about 654.2124216841.

The spelling of 279998921 in words is "two hundred seventy-nine million, nine hundred ninety-eight thousand, nine hundred twenty-one".