638135884801 has 2 divisors, whose sum is σ = 638135884802. Its totient is φ = 638135884800.

The previous prime is 638135884753. The next prime is 638135884823. The reversal of 638135884801 is 108488531836.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 621345945025 + 16789939776 = 788255^2 + 129576^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-638135884801 is a prime.

It is not a weakly prime, because it can be changed into another prime (638135884601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319067942400 + 319067942401.

It is an arithmetic number, because the mean of its divisors is an integer number (319067942401).

Almost surely, 2^638135884801 is an apocalyptic number.

It is an amenable number.

638135884801 is a deficient number, since it is larger than the sum of its proper divisors (1).

638135884801 is an equidigital number, since it uses as much as digits as its factorization.

638135884801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4423680, while the sum is 55.

The spelling of 638135884801 in words is "six hundred thirty-eight billion, one hundred thirty-five million, eight hundred eighty-four thousand, eight hundred one".