211321864 has 32 divisors (see below), whose sum is σ = 429992640. Its totient is φ = 96782400.

The previous prime is 211321841. The next prime is 211321871. The reversal of 211321864 is 468123112.

It is a Smith number, since the sum of its digits (28) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5869 + ... + 21379.

It is an arithmetic number, because the mean of its divisors is an integer number (13437270).

Almost surely, 2^211321864 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 211321864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (214996320).

211321864 is an abundant number, since it is smaller than the sum of its proper divisors (218670776).

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

211321864 is a wasteful number, since it uses less digits than its factorization.

211321864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15661 (or 15657 counting only the distinct ones).

The product of its digits is 2304, while the sum is 28.

The square root of 211321864 is about 14536.9138402895. The cubic root of 211321864 is about 595.6367394361.

Adding to 211321864 its reverse (468123112), we get a palindrome (679444976).

The spelling of 211321864 in words is "two hundred eleven million, three hundred twenty-one thousand, eight hundred sixty-four".