212000021556 has 12 divisors (see below), whose sum is σ = 494666716992. Its totient is φ = 70666673848.

The previous prime is 212000021539. The next prime is 212000021567. The reversal of 212000021556 is 655120000212.

It is a happy number.

212000021556 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×212000021556² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8833334220 + ... + 8833334243.

It is an arithmetic number, because the mean of its divisors is an integer number (41222226416).

Almost surely, 2^212000021556 is an apocalyptic number.

It is an amenable number.

212000021556 is an abundant number, since it is smaller than the sum of its proper divisors (282666695436).

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

212000021556 is a wasteful number, since it uses less digits than its factorization.

212000021556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17666668470 (or 17666668468 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

Adding to 212000021556 its reverse (655120000212), we get a palindrome (867120021768).

The spelling of 212000021556 in words is "two hundred twelve billion, twenty-one thousand, five hundred fifty-six".