639552581691479 has 2 divisors, whose sum is σ = 639552581691480. Its totient is φ = 639552581691478.

The previous prime is 639552581691451. The next prime is 639552581691487. The reversal of 639552581691479 is 974196185255936.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 639552581691479 - 2⁸ = 639552581691223 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639552581691979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319776290845739 + 319776290845740.

It is an arithmetic number, because the mean of its divisors is an integer number (319776290845740).

Almost surely, 2^{639552581691479} is an apocalyptic number.

639552581691479 is a deficient number, since it is larger than the sum of its proper divisors (1).

639552581691479 is an equidigital number, since it uses as much as digits as its factorization.

639552581691479 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4408992000, while the sum is 80.

The spelling of 639552581691479 in words is "six hundred thirty-nine trillion, five hundred fifty-two billion, five hundred eighty-one million, six hundred ninety-one thousand, four hundred seventy-nine".