638083842545 has 4 divisors (see below), whose sum is σ = 765700611060. Its totient is φ = 510467074032.

The previous prime is 638083842533. The next prime is 638083842551. The reversal of 638083842545 is 545248380836.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 506102765281 + 131981077264 = 711409^2 + 363292^2 .

It is a cyclic number.

It is not a de Polignac number, because 638083842545 - 2⁶ = 638083842481 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63808384250 + ... + 63808384259.

It is an arithmetic number, because the mean of its divisors is an integer number (191425152765).

Almost surely, 2^638083842545 is an apocalyptic number.

It is an amenable number.

638083842545 is a deficient number, since it is larger than the sum of its proper divisors (127616768515).

638083842545 is a wasteful number, since it uses less digits than its factorization.

638083842545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127616768514.

The product of its (nonzero) digits is 22118400, while the sum is 56.

The spelling of 638083842545 in words is "six hundred thirty-eight billion, eighty-three million, eight hundred forty-two thousand, five hundred forty-five".