638475425281 has 8 divisors (see below), whose sum is σ = 644351063400. Its totient is φ = 632600115840.

The previous prime is 638475425267. The next prime is 638475425293. The reversal of 638475425281 is 182524574836.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 15821866225 + 622653559056 = 125785^2 + 789084^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 638475425281 - 2¹⁷ = 638475294209 is a prime.

It is a super-2 number, since 2×638475425281² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (638475422281) 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, 5651415 + ... + 5763283.

It is an arithmetic number, because the mean of its divisors is an integer number (80543882925).

Almost surely, 2^638475425281 is an apocalyptic number.

It is an amenable number.

638475425281 is a deficient number, since it is larger than the sum of its proper divisors (5875638119).

638475425281 is a wasteful number, since it uses less digits than its factorization.

638475425281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164339.

The product of its digits is 12902400, while the sum is 55.

The spelling of 638475425281 in words is "six hundred thirty-eight billion, four hundred seventy-five million, four hundred twenty-five thousand, two hundred eighty-one".