1639249693 has 2 divisors, whose sum is σ = 1639249694. Its totient is φ = 1639249692.

The previous prime is 1639249673. The next prime is 1639249709. The reversal of 1639249693 is 3969429361.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1208396644 + 430853049 = 34762^2 + 20757^2 .

It is an emirp because it is prime and its reverse (3969429361) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1639249693 - 2²¹ = 1637152541 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1639249693.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1639249603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 819624846 + 819624847.

It is an arithmetic number, because the mean of its divisors is an integer number (819624847).

Almost surely, 2^1639249693 is an apocalyptic number.

It is an amenable number.

1639249693 is a deficient number, since it is larger than the sum of its proper divisors (1).

1639249693 is an equidigital number, since it uses as much as digits as its factorization.

1639249693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1889568, while the sum is 52.

The square root of 1639249693 is about 40487.6486474579. The cubic root of 1639249693 is about 1179.0938396428.

The spelling of 1639249693 in words is "one billion, six hundred thirty-nine million, two hundred forty-nine thousand, six hundred ninety-three".