211531164 has 48 divisors (see below), whose sum is σ = 540277920. Its totient is φ = 64016640.

The previous prime is 211531157. The next prime is 211531169. The reversal of 211531164 is 461135112.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211531169) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1599 + ... + 20630.

It is an arithmetic number, because the mean of its divisors is an integer number (11255790).

Almost surely, 2^211531164 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 211531164, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (270138960).

211531164 is an abundant number, since it is smaller than the sum of its proper divisors (328746756).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

211531164 is a wasteful number, since it uses less digits than its factorization.

211531164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22310 (or 22308 counting only the distinct ones).

The product of its digits is 720, while the sum is 24.

The square root of 211531164 is about 14544.1109731740. The cubic root of 211531164 is about 595.8333205058.

Adding to 211531164 its reverse (461135112), we get a palindrome (672666276).

The spelling of 211531164 in words is "two hundred eleven million, five hundred thirty-one thousand, one hundred sixty-four".