209641031 has 2 divisors, whose sum is σ = 209641032. Its totient is φ = 209641030.

The previous prime is 209641007. The next prime is 209641097. The reversal of 209641031 is 130146902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 209641031 - 2⁶ = 209640967 is a prime.

It is a super-2 number, since 2×209641031² = 87898723757485922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209644031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104820515 + 104820516.

It is an arithmetic number, because the mean of its divisors is an integer number (104820516).

Almost surely, 2^209641031 is an apocalyptic number.

209641031 is a deficient number, since it is larger than the sum of its proper divisors (1).

209641031 is an equidigital number, since it uses as much as digits as its factorization.

209641031 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 209641031 is about 14478.9858415567. The cubic root of 209641031 is about 594.0533221602.

Adding to 209641031 its reverse (130146902), we get a palindrome (339787933).

The spelling of 209641031 in words is "two hundred nine million, six hundred forty-one thousand, thirty-one".