212221564651 has 4 divisors (see below), whose sum is σ = 213047329752. Its totient is φ = 211395799552.

The previous prime is 212221564649. The next prime is 212221564661. The reversal of 212221564651 is 156465122212.

212221564651 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 212221564651 - 2¹ = 212221564649 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 212221564651.

It is not an unprimeable number, because it can be changed into a prime (212221564661) by changing a digit.

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, 412882165 + ... + 412882678.

It is an arithmetic number, because the mean of its divisors is an integer number (53261832438).

Almost surely, 2^212221564651 is an apocalyptic number.

212221564651 is a deficient number, since it is larger than the sum of its proper divisors (825765101).

212221564651 is an equidigital number, since it uses as much as digits as its factorization.

212221564651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 825765100.

The product of its digits is 57600, while the sum is 37.

Adding to 212221564651 its reverse (156465122212), we get a palindrome (368686686863).

The spelling of 212221564651 in words is "two hundred twelve billion, two hundred twenty-one million, five hundred sixty-four thousand, six hundred fifty-one".