21633260 has 48 divisors (see below), whose sum is σ = 50077440. Its totient is φ = 7784640.

The previous prime is 21633253. The next prime is 21633289. The reversal of 21633260 is 6233612.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23081 + ... + 23999.

It is an arithmetic number, because the mean of its divisors is an integer number (1043280).

Almost surely, 2^21633260 is an apocalyptic number.

21633260 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21633260, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25038720).

21633260 is an abundant number, since it is smaller than the sum of its proper divisors (28444180).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21633260 is a wasteful number, since it uses less digits than its factorization.

21633260 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1046 (or 1044 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 23.

The square root of 21633260 is about 4651.1568453450. The cubic root of 21633260 is about 278.6382004555.

Adding to 21633260 its reverse (6233612), we get a palindrome (27866872).

The spelling of 21633260 in words is "twenty-one million, six hundred thirty-three thousand, two hundred sixty".