215035661 has 2 divisors, whose sum is σ = 215035662. Its totient is φ = 215035660.

The previous prime is 215035657. The next prime is 215035687. The reversal of 215035661 is 166530512.

215035661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 187525636 + 27510025 = 13694^2 + 5245^2 .

It is a cyclic number.

It is not a de Polignac number, because 215035661 - 2² = 215035657 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 (215035061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107517830 + 107517831.

It is an arithmetic number, because the mean of its divisors is an integer number (107517831).

Almost surely, 2^215035661 is an apocalyptic number.

It is an amenable number.

215035661 is a deficient number, since it is larger than the sum of its proper divisors (1).

215035661 is an equidigital number, since it uses as much as digits as its factorization.

215035661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 215035661 is about 14664.0942782021. The cubic root of 215035661 is about 599.1057614095.

The spelling of 215035661 in words is "two hundred fifteen million, thirty-five thousand, six hundred sixty-one".