211694661 has 16 divisors (see below), whose sum is σ = 314798400. Its totient is φ = 140600304.

The previous prime is 211694647. The next prime is 211694663. The reversal of 211694661 is 166496112.

It is not a de Polignac number, because 211694661 - 2¹³ = 211686469 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211694663) 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 15 ways as a sum of consecutive naturals, for example, 7311 + ... + 21836.

It is an arithmetic number, because the mean of its divisors is an integer number (19674900).

Almost surely, 2^211694661 is an apocalyptic number.

It is an amenable number.

211694661 is a deficient number, since it is larger than the sum of its proper divisors (103103739).

211694661 is a wasteful number, since it uses less digits than its factorization.

211694661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29425 (or 29419 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 211694661 is about 14549.7306160630. The cubic root of 211694661 is about 595.9867917812.

The spelling of 211694661 in words is "two hundred eleven million, six hundred ninety-four thousand, six hundred sixty-one".