21440633 has 4 divisors (see below), whose sum is σ = 21450240. Its totient is φ = 21431028.

The previous prime is 21440609. The next prime is 21440647. The reversal of 21440633 is 33604412.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21440633 - 2¹⁶ = 21375097 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21440599 and 21440608.

It is not an unprimeable number, because it can be changed into a prime (21440693) 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, 488 + ... + 6566.

It is an arithmetic number, because the mean of its divisors is an integer number (5362560).

Almost surely, 2^21440633 is an apocalyptic number.

It is an amenable number.

21440633 is a deficient number, since it is larger than the sum of its proper divisors (9607).

21440633 is an equidigital number, since it uses as much as digits as its factorization.

21440633 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9606.

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 21440633 is about 4630.4031142007. The cubic root of 21440633 is about 277.8087162992.

The spelling of 21440633 in words is "twenty-one million, four hundred forty thousand, six hundred thirty-three".