21084746400 has 324 divisors, whose sum is σ = 78988682682. Its totient is φ = 5291335680.

The previous prime is 21084746399. The next prime is 21084746411. The reversal of 21084746400 is 464748012.

21084746400 is a `hidden beast` number, since 2 + 1 + 0 + 8 + 4 + 7 + 4 + 640 + 0 = 666.

It can be written as a sum of positive squares in 9 ways, for example, as 8925714576 + 12159031824 = 94476^2 + 110268^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 2075734 + ... + 2085866.

Almost surely, 2^21084746400 is an apocalyptic number.

21084746400 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 21084746400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39494341341).

21084746400 is an abundant number, since it is smaller than the sum of its proper divisors (57903936282).

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

21084746400 is a wasteful number, since it uses less digits than its factorization.

21084746400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10193 (or 10160 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 36.

The spelling of 21084746400 in words is "twenty-one billion, eighty-four million, seven hundred forty-six thousand, four hundred".