209031001 has 2 divisors, whose sum is σ = 209031002. Its totient is φ = 209031000.

The previous prime is 209030999. The next prime is 209031013. The reversal of 209031001 is 100130902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 197121600 + 11909401 = 14040^2 + 3451^2 .

It is a cyclic number.

It is not a de Polignac number, because 209031001 - 2¹ = 209030999 is a prime.

Together with 209030999, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (209031091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104515500 + 104515501.

It is an arithmetic number, because the mean of its divisors is an integer number (104515501).

Almost surely, 2^209031001 is an apocalyptic number.

It is an amenable number.

209031001 is a deficient number, since it is larger than the sum of its proper divisors (1).

209031001 is an equidigital number, since it uses as much as digits as its factorization.

209031001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54, while the sum is 16.

The square root of 209031001 is about 14457.9044470490. The cubic root of 209031001 is about 593.4765546262.

Adding to 209031001 its reverse (100130902), we get a palindrome (309161903).

It can be divided in two parts, 20903 and 1001, that added together give a square (21904 = 148²).

The spelling of 209031001 in words is "two hundred nine million, thirty-one thousand, one".