21738863 has 4 divisors (see below), whose sum is σ = 22201440. Its totient is φ = 21276288.

The previous prime is 21738853. The next prime is 21738877. The reversal of 21738863 is 36883712.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21738863 - 2¹⁰ = 21737839 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21738803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 231218 + ... + 231311.

It is an arithmetic number, because the mean of its divisors is an integer number (5550360).

Almost surely, 2^21738863 is an apocalyptic number.

21738863 is a deficient number, since it is larger than the sum of its proper divisors (462577).

21738863 is an equidigital number, since it uses as much as digits as its factorization.

21738863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 462576.

The product of its digits is 48384, while the sum is 38.

The square root of 21738863 is about 4662.4953619280. The cubic root of 21738863 is about 279.0908565319.

The spelling of 21738863 in words is "twenty-one million, seven hundred thirty-eight thousand, eight hundred sixty-three".