210051661 has 2 divisors, whose sum is σ = 210051662. Its totient is φ = 210051660.

The previous prime is 210051641. The next prime is 210051671. The reversal of 210051661 is 166150012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 209380900 + 670761 = 14470^2 + 819^2 .

It is a cyclic number.

It is not a de Polignac number, because 210051661 - 2¹¹ = 210049613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (210051641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105025830 + 105025831.

It is an arithmetic number, because the mean of its divisors is an integer number (105025831).

Almost surely, 2^210051661 is an apocalyptic number.

It is an amenable number.

210051661 is a deficient number, since it is larger than the sum of its proper divisors (1).

210051661 is an equidigital number, since it uses as much as digits as its factorization.

210051661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 210051661 is about 14493.1591104217. The cubic root of 210051661 is about 594.4409323835.

The spelling of 210051661 in words is "two hundred ten million, fifty-one thousand, six hundred sixty-one".