671742649 has 2 divisors, whose sum is σ = 671742650. Its totient is φ = 671742648.

The previous prime is 671742611. The next prime is 671742661. The reversal of 671742649 is 946247176.

671742649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 653722624 + 18020025 = 25568^2 + 4245^2 .

It is a cyclic number.

It is not a de Polignac number, because 671742649 - 2¹³ = 671734457 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 671742599 and 671742608.

It is not a weakly prime, because it can be changed into another prime (671742679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 335871324 + 335871325.

It is an arithmetic number, because the mean of its divisors is an integer number (335871325).

Almost surely, 2^671742649 is an apocalyptic number.

It is an amenable number.

671742649 is a deficient number, since it is larger than the sum of its proper divisors (1).

671742649 is an equidigital number, since it uses as much as digits as its factorization.

671742649 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 508032, while the sum is 46.

The square root of 671742649 is about 25917.9985531291. The cubic root of 671742649 is about 875.7920008410.

The spelling of 671742649 in words is "six hundred seventy-one million, seven hundred forty-two thousand, six hundred forty-nine".