21321634 has 8 divisors (see below), whose sum is σ = 32014620. Its totient is φ = 10650096.

The previous prime is 21321623. The next prime is 21321647. The reversal of 21321634 is 43612312.

It can be written as a sum of positive squares in 2 ways, for example, as 21298225 + 23409 = 4615^2 + 153^2 .

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

It is a super-2 number, since 2×21321634² = 909224152859912, which contains 22 as substring.

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, 2589 + ... + 7024.

Almost surely, 2^21321634 is an apocalyptic number.

21321634 is a deficient number, since it is larger than the sum of its proper divisors (10692986).

21321634 is a wasteful number, since it uses less digits than its factorization.

21321634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10724.

The product of its digits is 864, while the sum is 22.

The square root of 21321634 is about 4617.5354898474. The cubic root of 21321634 is about 277.2938013153.

Adding to 21321634 its reverse (43612312), we get a palindrome (64933946).

The spelling of 21321634 in words is "twenty-one million, three hundred twenty-one thousand, six hundred thirty-four".