638634334633 has 2 divisors, whose sum is σ = 638634334634. Its totient is φ = 638634334632.

The previous prime is 638634334621. The next prime is 638634334687. The reversal of 638634334633 is 336433436836.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 507190381929 + 131443952704 = 712173^2 + 362552^2 .

It is a cyclic number.

It is not a de Polignac number, because 638634334633 - 2¹⁷ = 638634203561 is a prime.

It is not a weakly prime, because it can be changed into another prime (638634334033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319317167316 + 319317167317.

It is an arithmetic number, because the mean of its divisors is an integer number (319317167317).

Almost surely, 2^638634334633 is an apocalyptic number.

It is an amenable number.

638634334633 is a deficient number, since it is larger than the sum of its proper divisors (1).

638634334633 is an equidigital number, since it uses as much as digits as its factorization.

638634334633 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20155392, while the sum is 52.

The spelling of 638634334633 in words is "six hundred thirty-eight billion, six hundred thirty-four million, three hundred thirty-four thousand, six hundred thirty-three".