21033332440 has 64 divisors (see below), whose sum is σ = 48356352000. Its totient is φ = 8231341440.

The previous prime is 21033332431. The next prime is 21033332459. The reversal of 21033332440 is 4423333012.

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, 476841 + ... + 519079.

It is an arithmetic number, because the mean of its divisors is an integer number (755568000).

Almost surely, 2^21033332440 is an apocalyptic number.

21033332440 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 21033332440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24178176000).

21033332440 is an abundant number, since it is smaller than the sum of its proper divisors (27323019560).

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

21033332440 is a wasteful number, since it uses less digits than its factorization.

21033332440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42520 (or 42516 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 25.

Adding to 21033332440 its reverse (4423333012), we get a palindrome (25456665452).

The spelling of 21033332440 in words is "twenty-one billion, thirty-three million, three hundred thirty-two thousand, four hundred forty".