21629744 has 20 divisors (see below), whose sum is σ = 42535224. Its totient is φ = 10652928.

The previous prime is 21629743. The next prime is 21629747. The reversal of 21629744 is 44792612.

It is not an unprimeable number, because it can be changed into a prime (21629743) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9017 + ... + 11160.

Almost surely, 2^21629744 is an apocalyptic number.

It is an amenable number.

21629744 is a deficient number, since it is larger than the sum of its proper divisors (20905480).

21629744 is a wasteful number, since it uses less digits than its factorization.

21629744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20252 (or 20246 counting only the distinct ones).

The product of its digits is 24192, while the sum is 35.

The square root of 21629744 is about 4650.7788595030. The cubic root of 21629744 is about 278.6231041795.

The spelling of 21629744 in words is "twenty-one million, six hundred twenty-nine thousand, seven hundred forty-four".