21197214720 has 1056 divisors, whose sum is σ = 88288911360. Its totient is φ = 4644864000.

The previous prime is 21197214719. The next prime is 21197214737. The reversal of 21197214720 is 2741279112.

21197214720 is a `hidden beast` number, since 2 + 119 + 72 + 1 + 472 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1056).

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 (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 298552285 + ... + 298552355.

Almost surely, 2^21197214720 is an apocalyptic number.

21197214720 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 21197214720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44144455680).

21197214720 is an abundant number, since it is smaller than the sum of its proper divisors (67091696640).

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

21197214720 is a wasteful number, since it uses less digits than its factorization.

21197214720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163 (or 142 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The spelling of 21197214720 in words is "twenty-one billion, one hundred ninety-seven million, two hundred fourteen thousand, seven hundred twenty".