21233408 has 108 divisors (see below), whose sum is σ = 52710672. Its totient is φ = 8355840.

The previous prime is 21233389. The next prime is 21233411. The reversal of 21233408 is 80433212.

It is a zygodrome in base 4.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 517868 + ... + 517908.

Almost surely, 2^21233408 is an apocalyptic number.

21233408 is a gapful number since it is divisible by the number (28) 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 21233408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26355336).

21233408 is an abundant number, since it is smaller than the sum of its proper divisors (31477264).

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

21233408 is an equidigital number, since it uses as much as digits as its factorization.

21233408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98 (or 67 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 21233408 is about 4607.9722221385. The cubic root of 21233408 is about 276.9108046477.

The spelling of 21233408 in words is "twenty-one million, two hundred thirty-three thousand, four hundred eight".