21629938 has 8 divisors (see below), whose sum is σ = 35394480. Its totient is φ = 9831780.

The previous prime is 21629921. The next prime is 21629947. The reversal of 21629938 is 83992612.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21629938.

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, 491568 + ... + 491611.

It is an arithmetic number, because the mean of its divisors is an integer number (4424310).

Almost surely, 2^21629938 is an apocalyptic number.

21629938 is a deficient number, since it is larger than the sum of its proper divisors (13764542).

21629938 is a wasteful number, since it uses less digits than its factorization.

21629938 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 983192.

The product of its digits is 46656, while the sum is 40.

The square root of 21629938 is about 4650.7997161779. The cubic root of 21629938 is about 278.6239371793.

It can be divided in two parts, 2162 and 9938, that added together give a square (12100 = 110²).

The spelling of 21629938 in words is "twenty-one million, six hundred twenty-nine thousand, nine hundred thirty-eight".