639448412693 has 2 divisors, whose sum is σ = 639448412694. Its totient is φ = 639448412692.

The previous prime is 639448412591. The next prime is 639448412699. The reversal of 639448412693 is 396214844936.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 505112968369 + 134335444324 = 710713^2 + 366518^2 .

It is a cyclic number.

It is not a de Polignac number, because 639448412693 - 2¹⁰ = 639448411669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639448412699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319724206346 + 319724206347.

It is an arithmetic number, because the mean of its divisors is an integer number (319724206347).

Almost surely, 2^639448412693 is an apocalyptic number.

It is an amenable number.

639448412693 is a deficient number, since it is larger than the sum of its proper divisors (1).

639448412693 is an equidigital number, since it uses as much as digits as its factorization.

639448412693 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26873856, while the sum is 59.

The spelling of 639448412693 in words is "six hundred thirty-nine billion, four hundred forty-eight million, four hundred twelve thousand, six hundred ninety-three".