21376279 has 2 divisors, whose sum is σ = 21376280. Its totient is φ = 21376278.

The previous prime is 21376253. The next prime is 21376297. The reversal of 21376279 is 97267312.

Together with next prime (21376297) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21376279 - 2¹¹ = 21374231 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21376679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10688139 + 10688140.

It is an arithmetic number, because the mean of its divisors is an integer number (10688140).

Almost surely, 2^21376279 is an apocalyptic number.

21376279 is a deficient number, since it is larger than the sum of its proper divisors (1).

21376279 is an equidigital number, since it uses as much as digits as its factorization.

21376279 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31752, while the sum is 37.

The square root of 21376279 is about 4623.4488209561. The cubic root of 21376279 is about 277.5304903867.

The spelling of 21376279 in words is "twenty-one million, three hundred seventy-six thousand, two hundred seventy-nine".