1639494673 has 2 divisors, whose sum is σ = 1639494674. Its totient is φ = 1639494672.

The previous prime is 1639494643. The next prime is 1639494683. The reversal of 1639494673 is 3764949361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1252664449 + 386830224 = 35393^2 + 19668^2 .

It is an emirp because it is prime and its reverse (3764949361) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1639494673 - 2⁵ = 1639494641 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1639494673.

It is not a weakly prime, because it can be changed into another prime (1639494643) 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, 819747336 + 819747337.

It is an arithmetic number, because the mean of its divisors is an integer number (819747337).

Almost surely, 2^1639494673 is an apocalyptic number.

It is an amenable number.

1639494673 is a deficient number, since it is larger than the sum of its proper divisors (1).

1639494673 is an equidigital number, since it uses as much as digits as its factorization.

1639494673 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2939328, while the sum is 52.

The square root of 1639494673 is about 40490.6739015295. The cubic root of 1639494673 is about 1179.1525738352.

The spelling of 1639494673 in words is "one billion, six hundred thirty-nine million, four hundred ninety-four thousand, six hundred seventy-three".