211690 has 8 divisors (see below), whose sum is σ = 381060. Its totient is φ = 84672.

The previous prime is 211681. The next prime is 211691. The reversal of 211690 is 96112.

It can be written as a sum of positive squares in 2 ways, for example, as 199809 + 11881 = 447^2 + 109^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×211690² = 89625312200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (211691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10575 + ... + 10594.

2²¹¹⁶⁹⁰ is an apocalyptic number.

211690 is a deficient number, since it is larger than the sum of its proper divisors (169370).

211690 is a wasteful number, since it uses less digits than its factorization.

211690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21176.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 211690 is about 460.0978156871. The cubic root of 211690 is about 59.5982417691.

It can be divided in two parts, 21 and 1690, that added together give a triangular number (1711 = T₅₈).

The spelling of 211690 in words is "two hundred eleven thousand, six hundred ninety".