211342661 has 4 divisors (see below), whose sum is σ = 214924800. Its totient is φ = 207760524.

The previous prime is 211342627. The next prime is 211342667. The reversal of 211342661 is 166243112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211342661 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 211342661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211342667) 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, 1790981 + ... + 1791098.

It is an arithmetic number, because the mean of its divisors is an integer number (53731200).

Almost surely, 2^211342661 is an apocalyptic number.

It is an amenable number.

211342661 is a deficient number, since it is larger than the sum of its proper divisors (3582139).

211342661 is an equidigital number, since it uses as much as digits as its factorization.

211342661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3582138.

The product of its digits is 1728, while the sum is 26.

The square root of 211342661 is about 14537.6291395812. The cubic root of 211342661 is about 595.6562784317.

Adding to 211342661 its reverse (166243112), we get a palindrome (377585773).

The spelling of 211342661 in words is "two hundred eleven million, three hundred forty-two thousand, six hundred sixty-one".