21612344 has 16 divisors (see below), whose sum is σ = 43640520. Its totient is φ = 9974880.

The previous prime is 21612319. The next prime is 21612373. The reversal of 21612344 is 44321612.

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, 103802 + ... + 104009.

Almost surely, 2^21612344 is an apocalyptic number.

It is an amenable number.

21612344 is an abundant number, since it is smaller than the sum of its proper divisors (22028176).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21612344 is a wasteful number, since it uses less digits than its factorization.

21612344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207830 (or 207826 counting only the distinct ones).

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

The square root of 21612344 is about 4648.9078287271. The cubic root of 21612344 is about 278.5483715552.

Adding to 21612344 its reverse (44321612), we get a palindrome (65933956).

The spelling of 21612344 in words is "twenty-one million, six hundred twelve thousand, three hundred forty-four".