21910169 has 2 divisors, whose sum is σ = 21910170. Its totient is φ = 21910168.

The previous prime is 21910159. The next prime is 21910171. The reversal of 21910169 is 96101912.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17330569 + 4579600 = 4163^2 + 2140^2 .

It is a cyclic number.

It is not a de Polignac number, because 21910169 - 2¹⁶ = 21844633 is a prime.

It is a super-2 number, since 2×21910169² = 960111011217122, which contains 22 as substring.

Together with 21910171, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21910159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10955084 + 10955085.

It is an arithmetic number, because the mean of its divisors is an integer number (10955085).

Almost surely, 2^21910169 is an apocalyptic number.

It is an amenable number.

21910169 is a deficient number, since it is larger than the sum of its proper divisors (1).

21910169 is an equidigital number, since it uses as much as digits as its factorization.

21910169 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 972, while the sum is 29.

The square root of 21910169 is about 4680.8299477764. The cubic root of 21910169 is about 279.8220340189.

The spelling of 21910169 in words is "twenty-one million, nine hundred ten thousand, one hundred sixty-nine".