639196673 has 2 divisors, whose sum is σ = 639196674. Its totient is φ = 639196672.

The previous prime is 639196661. The next prime is 639196697. The reversal of 639196673 is 376691936.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 627853249 + 11343424 = 25057^2 + 3368^2 .

It is a cyclic number.

It is not a de Polignac number, because 639196673 - 2⁶ = 639196609 is a prime.

It is not a weakly prime, because it can be changed into another prime (639196373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319598336 + 319598337.

It is an arithmetic number, because the mean of its divisors is an integer number (319598337).

Almost surely, 2^639196673 is an apocalyptic number.

It is an amenable number.

639196673 is a deficient number, since it is larger than the sum of its proper divisors (1).

639196673 is an equidigital number, since it uses as much as digits as its factorization.

639196673 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1102248, while the sum is 50.

The square root of 639196673 is about 25282.3391520642. The cubic root of 639196673 is about 861.4131593061.

The spelling of 639196673 in words is "six hundred thirty-nine million, one hundred ninety-six thousand, six hundred seventy-three".