21269563 has 8 divisors (see below), whose sum is σ = 24873728. Its totient is φ = 17806824.

The previous prime is 21269551. The next prime is 21269593. The reversal of 21269563 is 36596212.

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

It is not a de Polignac number, because 21269563 - 2²¹ = 19172411 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21269593) 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 in 7 ways as a sum of consecutive naturals, for example, 35031 + ... + 35632.

It is an arithmetic number, because the mean of its divisors is an integer number (3109216).

Almost surely, 2^21269563 is an apocalyptic number.

21269563 is a deficient number, since it is larger than the sum of its proper divisors (3604165).

21269563 is an equidigital number, since it uses as much as digits as its factorization.

21269563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70713.

The product of its digits is 19440, while the sum is 34.

The square root of 21269563 is about 4611.8936457815. The cubic root of 21269563 is about 277.0678846771.

The spelling of 21269563 in words is "twenty-one million, two hundred sixty-nine thousand, five hundred sixty-three".