21332643 has 8 divisors (see below), whose sum is σ = 28466256. Its totient is φ = 14210400.

The previous prime is 21332629. The next prime is 21332651. The reversal of 21332643 is 34623312.

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

It is not a de Polignac number, because 21332643 - 2⁶ = 21332579 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21332653) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3673 + ... + 7493.

It is an arithmetic number, because the mean of its divisors is an integer number (3558282).

Almost surely, 2^21332643 is an apocalyptic number.

21332643 is a deficient number, since it is larger than the sum of its proper divisors (7133613).

21332643 is a wasteful number, since it uses less digits than its factorization.

21332643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5685.

The product of its digits is 2592, while the sum is 24.

The square root of 21332643 is about 4618.7274221370. The cubic root of 21332643 is about 277.3415181430.

Adding to 21332643 its reverse (34623312), we get a palindrome (55955955).

The spelling of 21332643 in words is "twenty-one million, three hundred thirty-two thousand, six hundred forty-three".