21000344 has 16 divisors (see below), whose sum is σ = 39595920. Its totient is φ = 10441440.

The previous prime is 21000337. The next prime is 21000367. The reversal of 21000344 is 44300012.

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, 5804 + ... + 8699.

It is an arithmetic number, because the mean of its divisors is an integer number (2474745).

Almost surely, 2^21000344 is an apocalyptic number.

It is an amenable number.

21000344 is a deficient number, since it is larger than the sum of its proper divisors (18595576).

21000344 is a wasteful number, since it uses less digits than its factorization.

21000344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14690 (or 14686 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 21000344 is about 4582.6132282793. The cubic root of 21000344 is about 275.8939240901.

Adding to 21000344 its reverse (44300012), we get a palindrome (65300356).

The spelling of 21000344 in words is "twenty-one million, three hundred forty-four", and thus it is an aban number.