1611665213 has 2 divisors, whose sum is σ = 1611665214. Its totient is φ = 1611665212.

The previous prime is 1611665197. The next prime is 1611665219. The reversal of 1611665213 is 3125661161.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1588979044 + 22686169 = 39862^2 + 4763^2 .

It is a cyclic number.

It is not a de Polignac number, because 1611665213 - 2⁴ = 1611665197 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1611665213.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1611665219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 805832606 + 805832607.

It is an arithmetic number, because the mean of its divisors is an integer number (805832607).

Almost surely, 2^1611665213 is an apocalyptic number.

It is an amenable number.

1611665213 is a deficient number, since it is larger than the sum of its proper divisors (1).

1611665213 is an equidigital number, since it uses as much as digits as its factorization.

1611665213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 32.

The square root of 1611665213 is about 40145.5503511909. The cubic root of 1611665213 is about 1172.4426560911.

The spelling of 1611665213 in words is "one billion, six hundred eleven million, six hundred sixty-five thousand, two hundred thirteen".