21333000400 has 120 divisors (see below), whose sum is σ = 51899381600. Its totient is φ = 8426073600.

The previous prime is 21333000323. The next prime is 21333000407. The reversal of 21333000400 is 400033312.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21333000407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16523755 + ... + 16525045.

Almost surely, 2^21333000400 is an apocalyptic number.

21333000400 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 21333000400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25949690800).

21333000400 is an abundant number, since it is smaller than the sum of its proper divisors (30566381200).

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

21333000400 is a wasteful number, since it uses less digits than its factorization.

21333000400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1797 (or 1786 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 16.

Adding to 21333000400 its reverse (400033312), we get a palindrome (21733033712).

The spelling of 21333000400 in words is "twenty-one billion, three hundred thirty-three million, four hundred", and thus it is an aban number.