20840269 has 2 divisors, whose sum is σ = 20840270. Its totient is φ = 20840268.

The previous prime is 20840263. The next prime is 20840293. The reversal of 20840269 is 96204802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16892100 + 3948169 = 4110^2 + 1987^2 .

It is a cyclic number.

It is not a de Polignac number, because 20840269 - 2⁹ = 20839757 is a prime.

It is a super-2 number, since 2×20840269² = 868633623984722, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20840269.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20840263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10420134 + 10420135.

It is an arithmetic number, because the mean of its divisors is an integer number (10420135).

Almost surely, 2^20840269 is an apocalyptic number.

It is an amenable number.

20840269 is a deficient number, since it is larger than the sum of its proper divisors (1).

20840269 is an equidigital number, since it uses as much as digits as its factorization.

20840269 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 20840269 is about 4565.1143468702. The cubic root of 20840269 is about 275.1911354424.

The spelling of 20840269 in words is "twenty million, eight hundred forty thousand, two hundred sixty-nine".