21458279 has 2 divisors, whose sum is σ = 21458280. Its totient is φ = 21458278.

The previous prime is 21458257. The next prime is 21458303. The reversal of 21458279 is 97285412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21458279 - 2¹⁶ = 21392743 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21455279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10729139 + 10729140.

It is an arithmetic number, because the mean of its divisors is an integer number (10729140).

Almost surely, 2^21458279 is an apocalyptic number.

21458279 is a deficient number, since it is larger than the sum of its proper divisors (1).

21458279 is an equidigital number, since it uses as much as digits as its factorization.

21458279 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40320, while the sum is 38.

The square root of 21458279 is about 4632.3081719592. The cubic root of 21458279 is about 277.8849091422.

The spelling of 21458279 in words is "twenty-one million, four hundred fifty-eight thousand, two hundred seventy-nine".