21643342 has 16 divisors (see below), whose sum is σ = 37433952. Its totient is φ = 9192960.

The previous prime is 21643333. The next prime is 21643351. The reversal of 21643342 is 24334612.

It is an interprime number because it is at equal distance from previous prime (21643333) and next prime (21643351).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5259 + ... + 8422.

It is an arithmetic number, because the mean of its divisors is an integer number (2339622).

Almost surely, 2^21643342 is an apocalyptic number.

21643342 is a deficient number, since it is larger than the sum of its proper divisors (15790610).

21643342 is a wasteful number, since it uses less digits than its factorization.

21643342 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13803.

The product of its digits is 3456, while the sum is 25.

The square root of 21643342 is about 4652.2405354840. The cubic root of 21643342 is about 278.6814794010.

Adding to 21643342 its reverse (24334612), we get a palindrome (45977954).

The spelling of 21643342 in words is "twenty-one million, six hundred forty-three thousand, three hundred forty-two".