211908013 has 4 divisors (see below), whose sum is σ = 212039100. Its totient is φ = 211776928.

The previous prime is 211907989. The next prime is 211908019. The reversal of 211908013 is 310809112.

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 6215049 + 205692964 = 2493^2 + 14342^2 .

It is a cyclic number.

It is not a de Polignac number, because 211908013 - 2¹⁷ = 211776941 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 (211908019) 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, 63088 + ... + 66361.

It is an arithmetic number, because the mean of its divisors is an integer number (53009775).

Almost surely, 2^211908013 is an apocalyptic number.

It is an amenable number.

211908013 is a deficient number, since it is larger than the sum of its proper divisors (131087).

211908013 is a wasteful number, since it uses less digits than its factorization.

211908013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131086.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 211908013 is about 14557.0605892811. The cubic root of 211908013 is about 596.1869421306.

The spelling of 211908013 in words is "two hundred eleven million, nine hundred eight thousand, thirteen".