211231001 has 4 divisors (see below), whose sum is σ = 223656372. Its totient is φ = 198805632.

The previous prime is 211230997. The next prime is 211231049. The reversal of 211231001 is 100132112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 121000000 + 90231001 = 11000^2 + 9499^2 .

It is a cyclic number.

It is not a de Polignac number, because 211231001 - 2² = 211230997 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (211231051) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6212660 + ... + 6212693.

It is an arithmetic number, because the mean of its divisors is an integer number (55914093).

Almost surely, 2^211231001 is an apocalyptic number.

It is an amenable number.

211231001 is a deficient number, since it is larger than the sum of its proper divisors (12425371).

211231001 is a wasteful number, since it uses less digits than its factorization.

211231001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12425370.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 211231001 is about 14533.7882535834. The cubic root of 211231001 is about 595.5513576732.

Adding to 211231001 its reverse (100132112), we get a palindrome (311363113).

The spelling of 211231001 in words is "two hundred eleven million, two hundred thirty-one thousand, one".