212013391 has 4 divisors (see below), whose sum is σ = 213561072. Its totient is φ = 210465712.

The previous prime is 212013377. The next prime is 212013407. The reversal of 212013391 is 193310212.

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-212013391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212013301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 773635 + ... + 773908.

It is an arithmetic number, because the mean of its divisors is an integer number (53390268).

Almost surely, 2^212013391 is an apocalyptic number.

212013391 is a deficient number, since it is larger than the sum of its proper divisors (1547681).

212013391 is a wasteful number, since it uses less digits than its factorization.

212013391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1547680.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 212013391 is about 14560.6796201276. The cubic root of 212013391 is about 596.2857500609.

The spelling of 212013391 in words is "two hundred twelve million, thirteen thousand, three hundred ninety-one".