211912043861 has 12 divisors (see below), whose sum is σ = 246561420492. Its totient is φ = 181600953408.

The previous prime is 211912043839. The next prime is 211912043867. The reversal of 211912043861 is 168340219112.

It can be written as a sum of positive squares in 2 ways, for example, as 172482396100 + 39429647761 = 415310^2 + 198569^2 .

It is a de Polignac number, because none of the positive numbers 2^k-211912043861 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211912043867) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 213440 + ... + 685113.

It is an arithmetic number, because the mean of its divisors is an integer number (20546785041).

Almost surely, 2^211912043861 is an apocalyptic number.

It is an amenable number.

211912043861 is a deficient number, since it is larger than the sum of its proper divisors (34649376631).

211912043861 is an equidigital number, since it uses as much as digits as its factorization.

211912043861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 903380 (or 903373 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 38.

The spelling of 211912043861 in words is "two hundred eleven billion, nine hundred twelve million, forty-three thousand, eight hundred sixty-one".