212151311821 has 2 divisors, whose sum is σ = 212151311822. Its totient is φ = 212151311820.

The previous prime is 212151311807. The next prime is 212151311839. The reversal of 212151311821 is 128113151212.

212151311821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 211922122500 + 229189321 = 460350^2 + 15139^2 .

It is a cyclic number.

It is not a de Polignac number, because 212151311821 - 2³¹ = 210003828173 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 212151311821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212151314821) 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 as a sum of consecutive naturals, namely, 106075655910 + 106075655911.

It is an arithmetic number, because the mean of its divisors is an integer number (106075655911).

Almost surely, 2^212151311821 is an apocalyptic number.

It is an amenable number.

212151311821 is a deficient number, since it is larger than the sum of its proper divisors (1).

212151311821 is an equidigital number, since it uses as much as digits as its factorization.

212151311821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 960, while the sum is 28.

The spelling of 212151311821 in words is "two hundred twelve billion, one hundred fifty-one million, three hundred eleven thousand, eight hundred twenty-one".