21032402400 has 216 divisors, whose sum is σ = 74281105080. Its totient is φ = 5599902720.

The previous prime is 21032402399. The next prime is 21032402407. The reversal of 21032402400 is 420423012.

21032402400 is a `hidden beast` number, since 21 + 0 + 3 + 240 + 2 + 400 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21032402407) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 5563711 + ... + 5567489.

It is an arithmetic number, because the mean of its divisors is an integer number (343894005).

Almost surely, 2^21032402400 is an apocalyptic number.

21032402400 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 21032402400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37140552540).

21032402400 is an abundant number, since it is smaller than the sum of its proper divisors (53248702680).

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

21032402400 is a wasteful number, since it uses less digits than its factorization.

21032402400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4578 (or 4562 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

Adding to 21032402400 its reverse (420423012), we get a palindrome (21452825412).

The spelling of 21032402400 in words is "twenty-one billion, thirty-two million, four hundred two thousand, four hundred".