21612443 has 8 divisors (see below), whose sum is σ = 22854720. Its totient is φ = 20380680.

The previous prime is 21612431. The next prime is 21612497. The reversal of 21612443 is 34421612.

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

It is a cyclic number.

It is not a de Polignac number, because 21612443 - 2⁶ = 21612379 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21612413) 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, 1808 + ... + 6818.

It is an arithmetic number, because the mean of its divisors is an integer number (2856840).

Almost surely, 2^21612443 is an apocalyptic number.

21612443 is a deficient number, since it is larger than the sum of its proper divisors (1242277).

21612443 is a wasteful number, since it uses less digits than its factorization.

21612443 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5257.

The product of its digits is 1152, while the sum is 23.

The square root of 21612443 is about 4648.9184763771. The cubic root of 21612443 is about 278.5487968715.

The spelling of 21612443 in words is "twenty-one million, six hundred twelve thousand, four hundred forty-three".