258279821 has 2 divisors, whose sum is σ = 258279822. Its totient is φ = 258279820.

The previous prime is 258279809. The next prime is 258279823. The reversal of 258279821 is 128972852.

258279821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 149181796 + 109098025 = 12214^2 + 10445^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-258279821 is a prime.

Together with 258279823, 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 (258279823) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 129139910 + 129139911.

It is an arithmetic number, because the mean of its divisors is an integer number (129139911).

Almost surely, 2^258279821 is an apocalyptic number.

It is an amenable number.

258279821 is a deficient number, since it is larger than the sum of its proper divisors (1).

258279821 is an equidigital number, since it uses as much as digits as its factorization.

258279821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 161280, while the sum is 44.

The square root of 258279821 is about 16071.0864909626. The cubic root of 258279821 is about 636.8397437341.

The spelling of 258279821 in words is "two hundred fifty-eight million, two hundred seventy-nine thousand, eight hundred twenty-one".