21344813 has 8 divisors (see below), whose sum is σ = 24961728. Its totient is φ = 17869824.

The previous prime is 21344803. The next prime is 21344821. The reversal of 21344813 is 31844312.

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

It is not a de Polignac number, because 21344813 - 2²⁴ = 4567597 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 (21344803) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35156 + ... + 35757.

It is an arithmetic number, because the mean of its divisors is an integer number (3120216).

Almost surely, 2^21344813 is an apocalyptic number.

It is an amenable number.

21344813 is a deficient number, since it is larger than the sum of its proper divisors (3616915).

21344813 is an equidigital number, since it uses as much as digits as its factorization.

21344813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70963.

The product of its digits is 2304, while the sum is 26.

The square root of 21344813 is about 4620.0446967535. The cubic root of 21344813 is about 277.3942480467.

The spelling of 21344813 in words is "twenty-one million, three hundred forty-four thousand, eight hundred thirteen".