21275179 has 2 divisors, whose sum is σ = 21275180. Its totient is φ = 21275178.

The previous prime is 21275171. The next prime is 21275197. The reversal of 21275179 is 97157212.

Together with next prime (21275197) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21275179 - 2³ = 21275171 is a prime.

It is not a weakly prime, because it can be changed into another prime (21275171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10637589 + 10637590.

It is an arithmetic number, because the mean of its divisors is an integer number (10637590).

Almost surely, 2^21275179 is an apocalyptic number.

21275179 is a deficient number, since it is larger than the sum of its proper divisors (1).

21275179 is an equidigital number, since it uses as much as digits as its factorization.

21275179 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8820, while the sum is 34.

The square root of 21275179 is about 4612.5024661240. The cubic root of 21275179 is about 277.0922681323.

The spelling of 21275179 in words is "twenty-one million, two hundred seventy-five thousand, one hundred seventy-nine".