21344638 has 32 divisors (see below), whose sum is σ = 39859200. Its totient is φ = 8364384.

The previous prime is 21344629. The next prime is 21344663. The reversal of 21344638 is 83644312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6331 + ... + 9097.

It is an arithmetic number, because the mean of its divisors is an integer number (1245600).

Almost surely, 2^21344638 is an apocalyptic number.

21344638 is a deficient number, since it is larger than the sum of its proper divisors (18514562).

21344638 is a wasteful number, since it uses less digits than its factorization.

21344638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2824.

The product of its digits is 13824, while the sum is 31.

The square root of 21344638 is about 4620.0257575040. The cubic root of 21344638 is about 277.3934899527.

The spelling of 21344638 in words is "twenty-one million, three hundred forty-four thousand, six hundred thirty-eight".