212105305397 has 4 divisors (see below), whose sum is σ = 214051225740. Its totient is φ = 210159385056.

The previous prime is 212105305351. The next prime is 212105305427. The reversal of 212105305397 is 793503501212.

It is a happy number.

212105305397 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 can be written as a sum of positive squares in 2 ways, for example, as 113731492081 + 98373813316 = 337241^2 + 313646^2 .

It is a cyclic number.

It is not a de Polignac number, because 212105305397 - 2¹⁰ = 212105304373 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 212105305397.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212105305597) 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, 972960008 + ... + 972960225.

It is an arithmetic number, because the mean of its divisors is an integer number (53512806435).

Almost surely, 2^212105305397 is an apocalyptic number.

It is an amenable number.

212105305397 is a deficient number, since it is larger than the sum of its proper divisors (1945920343).

212105305397 is a wasteful number, since it uses less digits than its factorization.

212105305397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1945920342.

The product of its (nonzero) digits is 56700, while the sum is 38.

The spelling of 212105305397 in words is "two hundred twelve billion, one hundred five million, three hundred five thousand, three hundred ninety-seven".