21133040 has 80 divisors (see below), whose sum is σ = 53434080. Its totient is φ = 7741440.

The previous prime is 21133027. The next prime is 21133087. The reversal of 21133040 is 4033112.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55571 + ... + 55949.

It is an arithmetic number, because the mean of its divisors is an integer number (667926).

Almost surely, 2^21133040 is an apocalyptic number.

21133040 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 21133040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26717040).

21133040 is an abundant number, since it is smaller than the sum of its proper divisors (32301040).

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

21133040 is a wasteful number, since it uses less digits than its factorization.

21133040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 450 (or 444 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 21133040 is about 4597.0686312040. The cubic root of 21133040 is about 276.4738063340.

Adding to 21133040 its product of nonzero digits (72), we get a palindrome (21133112).

Adding to 21133040 its reverse (4033112), we get a palindrome (25166152).

The spelling of 21133040 in words is "twenty-one million, one hundred thirty-three thousand, forty".