21391603200 has 960 divisors, whose sum is σ = 90968106240. Its totient is φ = 4866048000.

The previous prime is 21391603187. The next prime is 21391603213. The reversal of 21391603200 is 230619312.

21391603200 is a `hidden beast` number, since 2 + 1 + 39 + 1 + 603 + 20 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21391603187) and next prime (21391603213).

It is a tau number, because it is divible by the number of its divisors (960).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 64627035 + ... + 64627365.

It is an arithmetic number, because the mean of its divisors is an integer number (94758444).

Almost surely, 2^21391603200 is an apocalyptic number.

21391603200 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 21391603200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45484053120).

21391603200 is an abundant number, since it is smaller than the sum of its proper divisors (69576503040).

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

21391603200 is a wasteful number, since it uses less digits than its factorization.

21391603200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 396 (or 369 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The spelling of 21391603200 in words is "twenty-one billion, three hundred ninety-one million, six hundred three thousand, two hundred".