21633480 has 160 divisors (see below), whose sum is σ = 79453440. Its totient is φ = 5235840.

The previous prime is 21633427. The next prime is 21633499. The reversal of 21633480 is 8433612.

It is a happy number.

21633480 is a `hidden beast` number, since 21 + 633 + 4 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 35337 + ... + 35943.

It is an arithmetic number, because the mean of its divisors is an integer number (496584).

Almost surely, 2^21633480 is an apocalyptic number.

21633480 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 21633480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39726720).

21633480 is an abundant number, since it is smaller than the sum of its proper divisors (57819960).

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

21633480 is a wasteful number, since it uses less digits than its factorization.

21633480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641 (or 628 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 21633480 is about 4651.1804953151. The cubic root of 21633480 is about 278.6391449918.

The spelling of 21633480 in words is "twenty-one million, six hundred thirty-three thousand, four hundred eighty".