661380658163 has 2 divisors, whose sum is σ = 661380658164. Its totient is φ = 661380658162.

The previous prime is 661380658157. The next prime is 661380658187. The reversal of 661380658163 is 361856083166.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661380658163 is a prime.

It is not a weakly prime, because it can be changed into another prime (661380658123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330690329081 + 330690329082.

It is an arithmetic number, because the mean of its divisors is an integer number (330690329082).

Almost surely, 2^661380658163 is an apocalyptic number.

661380658163 is a deficient number, since it is larger than the sum of its proper divisors (1).

661380658163 is an equidigital number, since it uses as much as digits as its factorization.

661380658163 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3732480, while the sum is 53.

The spelling of 661380658163 in words is "six hundred sixty-one billion, three hundred eighty million, six hundred fifty-eight thousand, one hundred sixty-three".