21280974400 has 189 divisors, whose sum is σ = 61030944867. Its totient is φ = 7282329600.

The previous prime is 21280974397. The next prime is 21280974409. The reversal of 21280974400 is 447908212.

The square root of 21280974400 is 145880.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 2671649344 + 18609325056 = 51688^2 + 136416^2 .

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21280974400.

It is not an unprimeable number, because it can be changed into a prime (21280974409) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 40846140 + ... + 40846660.

Almost surely, 2^21280974400 is an apocalyptic number.

21280974400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

21280974400 is the 145880-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21280974400

21280974400 is an abundant number, since it is smaller than the sum of its proper divisors (39749970467).

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

21280974400 is an frugal number, since it uses more digits than its factorization.

21280974400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1078 (or 535 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 37.

The spelling of 21280974400 in words is "twenty-one billion, two hundred eighty million, nine hundred seventy-four thousand, four hundred".