211138765 has 8 divisors (see below), whose sum is σ = 253546488. Its totient is φ = 168791040.

The previous prime is 211138747. The next prime is 211138769. The reversal of 211138765 is 567831112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 62932489 + 148206276 = 7933^2 + 12174^2 .

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

It is not a de Polignac number, because 211138765 - 2⁹ = 211138253 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 211138765.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211138769) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6852 + ... + 21661.

It is an arithmetic number, because the mean of its divisors is an integer number (31693311).

Almost surely, 2^211138765 is an apocalyptic number.

It is an amenable number.

211138765 is a deficient number, since it is larger than the sum of its proper divisors (42407723).

211138765 is a wasteful number, since it uses less digits than its factorization.

211138765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29999.

The product of its digits is 10080, while the sum is 34.

The square root of 211138765 is about 14530.6147495555. The cubic root of 211138765 is about 595.4646606889.

Adding to 211138765 its reverse (567831112), we get a palindrome (778969877).

The spelling of 211138765 in words is "two hundred eleven million, one hundred thirty-eight thousand, seven hundred sixty-five".