21401269 has 2 divisors, whose sum is σ = 21401270. Its totient is φ = 21401268.

The previous prime is 21401257. The next prime is 21401287. The reversal of 21401269 is 96210412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12341169 + 9060100 = 3513^2 + 3010^2 .

It is a cyclic number.

It is not a de Polignac number, because 21401269 - 2¹¹ = 21399221 is a prime.

It is a super-2 number, since 2×21401269² = 916028629620722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21401299) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10700634 + 10700635.

It is an arithmetic number, because the mean of its divisors is an integer number (10700635).

Almost surely, 2^21401269 is an apocalyptic number.

It is an amenable number.

21401269 is a deficient number, since it is larger than the sum of its proper divisors (1).

21401269 is an equidigital number, since it uses as much as digits as its factorization.

21401269 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 21401269 is about 4626.1505595906. The cubic root of 21401269 is about 277.6385975407.

The spelling of 21401269 in words is "twenty-one million, four hundred one thousand, two hundred sixty-nine".