674777561 has 2 divisors, whose sum is σ = 674777562. Its totient is φ = 674777560.

The previous prime is 674777507. The next prime is 674777563. The reversal of 674777561 is 165777476.

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., 559086025 + 115691536 = 23645^2 + 10756^2 .

It is a cyclic number.

It is not a de Polignac number, because 674777561 - 2⁶ = 674777497 is a prime.

Together with 674777563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (674777563) 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, 337388780 + 337388781.

It is an arithmetic number, because the mean of its divisors is an integer number (337388781).

Almost surely, 2^674777561 is an apocalyptic number.

It is an amenable number.

674777561 is a deficient number, since it is larger than the sum of its proper divisors (1).

674777561 is an equidigital number, since it uses as much as digits as its factorization.

674777561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728720, while the sum is 50.

The square root of 674777561 is about 25976.4809202478. The cubic root of 674777561 is about 877.1089530134.

The spelling of 674777561 in words is "six hundred seventy-four million, seven hundred seventy-seven thousand, five hundred sixty-one".