212831309291 has 4 divisors (see below), whose sum is σ = 212852410584. Its totient is φ = 212810208000.

The previous prime is 212831309269. The next prime is 212831309297. The reversal of 212831309291 is 192903138212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212831309291 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (212831309297) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10535510 + ... + 10555691.

It is an arithmetic number, because the mean of its divisors is an integer number (53213102646).

Almost surely, 2^212831309291 is an apocalyptic number.

212831309291 is a deficient number, since it is larger than the sum of its proper divisors (21101293).

212831309291 is a wasteful number, since it uses less digits than its factorization.

212831309291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21101292.

The product of its (nonzero) digits is 46656, while the sum is 41.

The spelling of 212831309291 in words is "two hundred twelve billion, eight hundred thirty-one million, three hundred nine thousand, two hundred ninety-one".