21544316 has 12 divisors (see below), whose sum is σ = 37787232. Its totient is φ = 10747968.

The previous prime is 21544301. The next prime is 21544331. The reversal of 21544316 is 61344512.

It is an interprime number because it is at equal distance from previous prime (21544301) and next prime (21544331).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3965 + ... + 7668.

It is an arithmetic number, because the mean of its divisors is an integer number (3148936).

Almost surely, 2^21544316 is an apocalyptic number.

It is an amenable number.

21544316 is a deficient number, since it is larger than the sum of its proper divisors (16242916).

21544316 is a wasteful number, since it uses less digits than its factorization.

21544316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12100 (or 12098 counting only the distinct ones).

The product of its digits is 2880, while the sum is 26.

The square root of 21544316 is about 4641.5855049756. The cubic root of 21544316 is about 278.2558071897.

Adding to 21544316 its reverse (61344512), we get a palindrome (82888828).

The spelling of 21544316 in words is "twenty-one million, five hundred forty-four thousand, three hundred sixteen".