638772385551 has 8 divisors (see below), whose sum is σ = 871503409920. Its totient is φ = 415944809112.

The previous prime is 638772385501. The next prime is 638772385567. The reversal of 638772385551 is 155583277836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 638772385551 - 2⁷ = 638772385423 is a prime.

It is a Smith number, since the sum of its digits (60) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638772385501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2475861831 + ... + 2475862088.

It is an arithmetic number, because the mean of its divisors is an integer number (108937926240).

Almost surely, 2^638772385551 is an apocalyptic number.

638772385551 is a deficient number, since it is larger than the sum of its proper divisors (232731024369).

638772385551 is a wasteful number, since it uses less digits than its factorization.

638772385551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4951723965.

The product of its digits is 42336000, while the sum is 60.

The spelling of 638772385551 in words is "six hundred thirty-eight billion, seven hundred seventy-two million, three hundred eighty-five thousand, five hundred fifty-one".