661327193 has 2 divisors, whose sum is σ = 661327194. Its totient is φ = 661327192.

The previous prime is 661327153. The next prime is 661327201. The reversal of 661327193 is 391723166.

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., 631165129 + 30162064 = 25123^2 + 5492^2 .

It is a cyclic number.

It is not a de Polignac number, because 661327193 - 2¹² = 661323097 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (661327153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330663596 + 330663597.

It is an arithmetic number, because the mean of its divisors is an integer number (330663597).

Almost surely, 2^661327193 is an apocalyptic number.

It is an amenable number.

661327193 is a deficient number, since it is larger than the sum of its proper divisors (1).

661327193 is an equidigital number, since it uses as much as digits as its factorization.

661327193 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40824, while the sum is 38.

The square root of 661327193 is about 25716.2826434926. The cubic root of 661327193 is about 871.2419804988.

The spelling of 661327193 in words is "six hundred sixty-one million, three hundred twenty-seven thousand, one hundred ninety-three".