279421 has 2 divisors, whose sum is σ = 279422. Its totient is φ = 279420.

The previous prime is 279413. The next prime is 279431. The reversal of 279421 is 124972.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 260100 + 19321 = 510^2 + 139^2 .

It is a cyclic number.

It is not a de Polignac number, because 279421 - 2³ = 279413 is a prime.

It is an Ulam number.

279421 is a lucky number.

It is equal to p₂₄₃₈₈ and since 279421 and 24388 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (279431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139710 + 139711.

It is an arithmetic number, because the mean of its divisors is an integer number (139711).

2²⁷⁹⁴²¹ is an apocalyptic number.

It is an amenable number.

279421 is a deficient number, since it is larger than the sum of its proper divisors (1).

279421 is an equidigital number, since it uses as much as digits as its factorization.

279421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1008, while the sum is 25.

The square root of 279421 is about 528.6028755124. The cubic root of 279421 is about 65.3762010998.

Subtracting from 279421 its reverse (124972), we obtain a square (154449 = 393²).

The spelling of 279421 in words is "two hundred seventy-nine thousand, four hundred twenty-one".