210133661 has 2 divisors, whose sum is σ = 210133662. Its totient is φ = 210133660.

The previous prime is 210133643. The next prime is 210133669. The reversal of 210133661 is 166331012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 201810436 + 8323225 = 14206^2 + 2885^2 .

It is a cyclic number.

It is not a de Polignac number, because 210133661 - 2¹⁴ = 210117277 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (210133669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105066830 + 105066831.

It is an arithmetic number, because the mean of its divisors is an integer number (105066831).

Almost surely, 2^210133661 is an apocalyptic number.

It is an amenable number.

210133661 is a deficient number, since it is larger than the sum of its proper divisors (1).

210133661 is an equidigital number, since it uses as much as digits as its factorization.

210133661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 210133661 is about 14495.9877552377. The cubic root of 210133661 is about 594.5182749678.

Adding to 210133661 its reverse (166331012), we get a palindrome (376464673).

The spelling of 210133661 in words is "two hundred ten million, one hundred thirty-three thousand, six hundred sixty-one".