21301279 has 2 divisors, whose sum is σ = 21301280. Its totient is φ = 21301278.

The previous prime is 21301277. The next prime is 21301321. The reversal of 21301279 is 97210312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21301279 - 2¹ = 21301277 is a prime.

Together with 21301277, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21301277) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10650639 + 10650640.

It is an arithmetic number, because the mean of its divisors is an integer number (10650640).

Almost surely, 2^21301279 is an apocalyptic number.

21301279 is a deficient number, since it is larger than the sum of its proper divisors (1).

21301279 is an equidigital number, since it uses as much as digits as its factorization.

21301279 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 756, while the sum is 25.

The square root of 21301279 is about 4615.3308657127. The cubic root of 21301279 is about 277.2055324015.

The spelling of 21301279 in words is "twenty-one million, three hundred one thousand, two hundred seventy-nine".