21970271 has 2 divisors, whose sum is σ = 21970272. Its totient is φ = 21970270.

The previous prime is 21970229. The next prime is 21970297. The reversal of 21970271 is 17207912.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21970271 - 2¹⁰ = 21969247 is a prime.

It is equal to p_1387505 and since 21970271 and 1387505 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21970771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10985135 + 10985136.

It is an arithmetic number, because the mean of its divisors is an integer number (10985136).

Almost surely, 2^21970271 is an apocalyptic number.

21970271 is a deficient number, since it is larger than the sum of its proper divisors (1).

21970271 is an equidigital number, since it uses as much as digits as its factorization.

21970271 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1764, while the sum is 29.

The square root of 21970271 is about 4687.2455664281. The cubic root of 21970271 is about 280.0776612809.

The spelling of 21970271 in words is "twenty-one million, nine hundred seventy thousand, two hundred seventy-one".