639473371 has 2 divisors, whose sum is σ = 639473372. Its totient is φ = 639473370.

The previous prime is 639473353. The next prime is 639473381. The reversal of 639473371 is 173374936.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 639473371 - 2¹⁵ = 639440603 is a prime.

It is not a weakly prime, because it can be changed into another prime (639473381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319736685 + 319736686.

It is an arithmetic number, because the mean of its divisors is an integer number (319736686).

Almost surely, 2^639473371 is an apocalyptic number.

639473371 is a deficient number, since it is larger than the sum of its proper divisors (1).

639473371 is an equidigital number, since it uses as much as digits as its factorization.

639473371 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 285768, while the sum is 43.

The square root of 639473371 is about 25287.8107197915. The cubic root of 639473371 is about 861.5374386940.

The spelling of 639473371 in words is "six hundred thirty-nine million, four hundred seventy-three thousand, three hundred seventy-one".