661164227 has 2 divisors, whose sum is σ = 661164228. Its totient is φ = 661164226.

The previous prime is 661164191. The next prime is 661164247. The reversal of 661164227 is 722461166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661164227 - 2²⁴ = 644387011 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (661164247) 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, 330582113 + 330582114.

It is an arithmetic number, because the mean of its divisors is an integer number (330582114).

Almost surely, 2^661164227 is an apocalyptic number.

661164227 is a deficient number, since it is larger than the sum of its proper divisors (1).

661164227 is an equidigital number, since it uses as much as digits as its factorization.

661164227 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24192, while the sum is 35.

The square root of 661164227 is about 25713.1139109988. The cubic root of 661164227 is about 871.1704100335.

The spelling of 661164227 in words is "six hundred sixty-one million, one hundred sixty-four thousand, two hundred twenty-seven".