21385469 has 16 divisors (see below), whose sum is σ = 26849280. Its totient is φ = 16608240.

The previous prime is 21385459. The next prime is 21385471. The reversal of 21385469 is 96458312.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21385469 - 2⁴ = 21385453 is a prime.

It is a super-2 number, since 2×21385469² = 914676568699922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21385409) 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 in 15 ways as a sum of consecutive naturals, for example, 437 + ... + 6554.

It is an arithmetic number, because the mean of its divisors is an integer number (1678080).

Almost surely, 2^21385469 is an apocalyptic number.

It is an amenable number.

21385469 is a deficient number, since it is larger than the sum of its proper divisors (5463811).

21385469 is a wasteful number, since it uses less digits than its factorization.

21385469 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7040.

The product of its digits is 51840, while the sum is 38.

The square root of 21385469 is about 4624.4425610013. The cubic root of 21385469 is about 277.5702562692.

The spelling of 21385469 in words is "twenty-one million, three hundred eighty-five thousand, four hundred sixty-nine".