21212710272 has 576 divisors, whose sum is σ = 71670034800. Its totient is φ = 6207860736.

The previous prime is 21212710193. The next prime is 21212710283. The reversal of 21212710272 is 27201721212.

21212710272 is a `hidden beast` number, since 2 + 121 + 271 + 0 + 272 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

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

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 316607583 + ... + 316607649.

Almost surely, 2^21212710272 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21212710272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35835017400).

21212710272 is an abundant number, since it is smaller than the sum of its proper divisors (50457324528).

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

21212710272 is an frugal number, since it uses more digits than its factorization.

21212710272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147 (or 114 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 27.

The spelling of 21212710272 in words is "twenty-one billion, two hundred twelve million, seven hundred ten thousand, two hundred seventy-two".