661774027 has 2 divisors, whose sum is σ = 661774028. Its totient is φ = 661774026.

The previous prime is 661773967. The next prime is 661774037. The reversal of 661774027 is 720477166.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661774027 - 2⁷ = 661773899 is a prime.

It is not a weakly prime, because it can be changed into another prime (661774037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330887013 + 330887014.

It is an arithmetic number, because the mean of its divisors is an integer number (330887014).

Almost surely, 2^661774027 is an apocalyptic number.

661774027 is a deficient number, since it is larger than the sum of its proper divisors (1).

661774027 is an equidigital number, since it uses as much as digits as its factorization.

661774027 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 98784, while the sum is 40.

The square root of 661774027 is about 25724.9689407004. The cubic root of 661774027 is about 871.4381581738.

The spelling of 661774027 in words is "six hundred sixty-one million, seven hundred seventy-four thousand, twenty-seven".