21003451200 has 336 divisors, whose sum is σ = 80598264000. Its totient is φ = 5305927680.

The previous prime is 21003451171. The next prime is 21003451229. The reversal of 21003451200 is 215430012.

21003451200 is a `hidden beast` number, since 2 + 10 + 0 + 3 + 451 + 200 = 666.

It is an interprime number because it is at equal distance from previous prime (21003451171) and next prime (21003451229).

It is a super-2 number, since 2×21003451200² (a number of 21 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 808006 + ... + 833594.

Almost surely, 2^21003451200 is an apocalyptic number.

21003451200 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 21003451200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40299132000).

21003451200 is an abundant number, since it is smaller than the sum of its proper divisors (59594812800).

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

21003451200 is a wasteful number, since it uses less digits than its factorization.

21003451200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25639 (or 25618 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

Adding to 21003451200 its reverse (215430012), we get a palindrome (21218881212).

The spelling of 21003451200 in words is "twenty-one billion, three million, four hundred fifty-one thousand, two hundred".