639535587913 has 2 divisors, whose sum is σ = 639535587914. Its totient is φ = 639535587912.

The previous prime is 639535587883. The next prime is 639535587979. The reversal of 639535587913 is 319785535936.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 560322611209 + 79212976704 = 748547^2 + 281448^2 .

It is a cyclic number.

It is not a de Polignac number, because 639535587913 - 2¹⁷ = 639535456841 is a prime.

It is not a weakly prime, because it can be changed into another prime (639535537913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319767793956 + 319767793957.

It is an arithmetic number, because the mean of its divisors is an integer number (319767793957).

Almost surely, 2^639535587913 is an apocalyptic number.

It is an amenable number.

639535587913 is a deficient number, since it is larger than the sum of its proper divisors (1).

639535587913 is an equidigital number, since it uses as much as digits as its factorization.

639535587913 is an evil number, because the sum of its binary digits is even.

The product of its digits is 91854000, while the sum is 64.

The spelling of 639535587913 in words is "six hundred thirty-nine billion, five hundred thirty-five million, five hundred eighty-seven thousand, nine hundred thirteen".