668775049 has 2 divisors, whose sum is σ = 668775050. Its totient is φ = 668775048.

The previous prime is 668775013. The next prime is 668775077. The reversal of 668775049 is 940577866.

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., 436517449 + 232257600 = 20893^2 + 15240^2 .

It is a cyclic number.

It is not a de Polignac number, because 668775049 - 2⁷ = 668774921 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 668774987 and 668775005.

It is not a weakly prime, because it can be changed into another prime (668775449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 334387524 + 334387525.

It is an arithmetic number, because the mean of its divisors is an integer number (334387525).

Almost surely, 2^668775049 is an apocalyptic number.

It is an amenable number.

668775049 is a deficient number, since it is larger than the sum of its proper divisors (1).

668775049 is an equidigital number, since it uses as much as digits as its factorization.

668775049 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2540160, while the sum is 52.

The square root of 668775049 is about 25860.6853930827. The cubic root of 668775049 is about 874.5004164212.

The spelling of 668775049 in words is "six hundred sixty-eight million, seven hundred seventy-five thousand, forty-nine".