211661293 has 2 divisors, whose sum is σ = 211661294. Its totient is φ = 211661292.

The previous prime is 211661287. The next prime is 211661299. The reversal of 211661293 is 392166112.

It is a balanced prime because it is at equal distance from previous prime (211661287) and next prime (211661299).

It can be written as a sum of positive squares in only one way, i.e., 202407529 + 9253764 = 14227^2 + 3042^2 .

It is a cyclic number.

It is not a de Polignac number, because 211661293 - 2²⁵ = 178106861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (211661299) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105830646 + 105830647.

It is an arithmetic number, because the mean of its divisors is an integer number (105830647).

Almost surely, 2^211661293 is an apocalyptic number.

It is an amenable number.

211661293 is a deficient number, since it is larger than the sum of its proper divisors (1).

211661293 is an equidigital number, since it uses as much as digits as its factorization.

211661293 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 31.

The square root of 211661293 is about 14548.5838829764. The cubic root of 211661293 is about 595.9554763446.

The spelling of 211661293 in words is "two hundred eleven million, six hundred sixty-one thousand, two hundred ninety-three".