21244259 has 2 divisors, whose sum is σ = 21244260. Its totient is φ = 21244258.

The previous prime is 21244247. The next prime is 21244277. The reversal of 21244259 is 95244212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21244259 - 2⁴ = 21244243 is a prime.

It is not a weakly prime, because it can be changed into another prime (21244219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10622129 + 10622130.

It is an arithmetic number, because the mean of its divisors is an integer number (10622130).

Almost surely, 2^21244259 is an apocalyptic number.

21244259 is a deficient number, since it is larger than the sum of its proper divisors (1).

21244259 is an equidigital number, since it uses as much as digits as its factorization.

21244259 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 29.

The square root of 21244259 is about 4609.1494877038. The cubic root of 21244259 is about 276.9579669220.

The spelling of 21244259 in words is "twenty-one million, two hundred forty-four thousand, two hundred fifty-nine".