211906249 has 3 divisors (see below), whose sum is σ = 211920807. Its totient is φ = 211891692.

The previous prime is 211906237. The next prime is 211906273. The reversal of 211906249 is 942609112.

The square root of 211906249 is 14557.

It is a perfect power (a square), and thus also a powerful number.

211906249 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 34164025 + 177742224 = 5845^2 + 13332^2 .

It is not a de Polignac number, because 211906249 - 2⁵ = 211906217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (211906549) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 7279 + ... + 21835.

It is an arithmetic number, because the mean of its divisors is an integer number (70640269).

Almost surely, 2^211906249 is an apocalyptic number.

211906249 is the 14557-th square number.

211906249 is the 7279-th centered octagonal number.

It is an amenable number.

211906249 is a deficient number, since it is larger than the sum of its proper divisors (14558).

211906249 is an frugal number, since it uses more digits than its factorization.

211906249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29114 (or 14557 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 34.

The cubic root of 211906249 is about 596.1852878331.

The spelling of 211906249 in words is "two hundred eleven million, nine hundred six thousand, two hundred forty-nine".