21583216 has 10 divisors (see below), whose sum is σ = 41817512. Its totient is φ = 10791600.

The previous prime is 21583201. The next prime is 21583231. The reversal of 21583216 is 61238512.

It is an interprime number because it is at equal distance from previous prime (21583201) and next prime (21583231).

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 674460 + ... + 674491.

Almost surely, 2^21583216 is an apocalyptic number.

It is an amenable number.

21583216 is a deficient number, since it is larger than the sum of its proper divisors (20234296).

21583216 is a wasteful number, since it uses less digits than its factorization.

21583216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1348959 (or 1348953 counting only the distinct ones).

The product of its digits is 2880, while the sum is 28.

The square root of 21583216 is about 4645.7739936420. The cubic root of 21583216 is about 278.4231775965.

The spelling of 21583216 in words is "twenty-one million, five hundred eighty-three thousand, two hundred sixteen".