21279283200 has 720 divisors, whose sum is σ = 90195945840. Its totient is φ = 4857200640.

The previous prime is 21279283189. The next prime is 21279283211. The reversal of 21279283200 is 238297212.

It is an interprime number because it is at equal distance from previous prime (21279283189) and next prime (21279283211).

It is a tau number, because it is divible by the number of its divisors (720).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 29030034 + ... + 29030766.

It is an arithmetic number, because the mean of its divisors is an integer number (125272147).

Almost surely, 2^21279283200 is an apocalyptic number.

21279283200 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 21279283200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45097972920).

21279283200 is an abundant number, since it is smaller than the sum of its proper divisors (68916662640).

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

21279283200 is an equidigital number, since it uses as much as digits as its factorization.

21279283200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 784 (or 750 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The spelling of 21279283200 in words is "twenty-one billion, two hundred seventy-nine million, two hundred eighty-three thousand, two hundred".