21468569 has 8 divisors (see below), whose sum is σ = 22795848. Its totient is φ = 20148480.

The previous prime is 21468563. The next prime is 21468581. The reversal of 21468569 is 96586412.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2849344 + 18619225 = 1688^2 + 4315^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21468569 - 2¹² = 21464473 is a prime.

It is a super-2 number, since 2×21468569² = 921798909815522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21468563) 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 7 ways as a sum of consecutive naturals, for example, 5159 + ... + 8339.

It is an arithmetic number, because the mean of its divisors is an integer number (2849481).

Almost surely, 2^21468569 is an apocalyptic number.

It is an amenable number.

21468569 is a deficient number, since it is larger than the sum of its proper divisors (1327279).

21468569 is a wasteful number, since it uses less digits than its factorization.

21468569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3595.

The product of its digits is 103680, while the sum is 41.

The square root of 21468569 is about 4633.4187162397. The cubic root of 21468569 is about 277.9293205754.

The spelling of 21468569 in words is "twenty-one million, four hundred sixty-eight thousand, five hundred sixty-nine".