21456633 has 16 divisors (see below), whose sum is σ = 32054976. Its totient is φ = 12651840.

The previous prime is 21456629. The next prime is 21456641. The reversal of 21456633 is 33665412.

It is not a de Polignac number, because 21456633 - 2² = 21456629 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21456633.

It is not an unprimeable number, because it can be changed into a prime (21456623) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7566 + ... + 10007.

It is an arithmetic number, because the mean of its divisors is an integer number (2003436).

Almost surely, 2^21456633 is an apocalyptic number.

It is an amenable number.

21456633 is a deficient number, since it is larger than the sum of its proper divisors (10598343).

21456633 is a wasteful number, since it uses less digits than its factorization.

21456633 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17624.

The product of its digits is 12960, while the sum is 30.

The square root of 21456633 is about 4632.1305033429. The cubic root of 21456633 is about 277.8778037222.

It can be divided in two parts, 2145 and 6633, that added together give a palindrome (8778).

The spelling of 21456633 in words is "twenty-one million, four hundred fifty-six thousand, six hundred thirty-three".