21052469 has 2 divisors, whose sum is σ = 21052470. Its totient is φ = 21052468.

The previous prime is 21052411. The next prime is 21052481. The reversal of 21052469 is 96425012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11992369 + 9060100 = 3463^2 + 3010^2 .

It is a cyclic number.

It is not a de Polignac number, because 21052469 - 2¹² = 21048373 is a prime.

It is a super-2 number, since 2×21052469² = 886412901991922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21052489) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10526234 + 10526235.

It is an arithmetic number, because the mean of its divisors is an integer number (10526235).

Almost surely, 2^21052469 is an apocalyptic number.

It is an amenable number.

21052469 is a deficient number, since it is larger than the sum of its proper divisors (1).

21052469 is an equidigital number, since it uses as much as digits as its factorization.

21052469 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 21052469 is about 4588.2969607470. The cubic root of 21052469 is about 276.1220011290.

The spelling of 21052469 in words is "twenty-one million, fifty-two thousand, four hundred sixty-nine".