638474751281 has 8 divisors (see below), whose sum is σ = 639712835328. Its totient is φ = 637236882000.

The previous prime is 638474751259. The next prime is 638474751437. The reversal of 638474751281 is 182157474836.

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 638474751281 - 2¹⁴ = 638474734897 is a prime.

It is a super-2 number, since 2×638474751281² (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 (638474751241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6721286 + ... + 6815616.

It is an arithmetic number, because the mean of its divisors is an integer number (79964104416).

Almost surely, 2^638474751281 is an apocalyptic number.

It is an amenable number.

638474751281 is a deficient number, since it is larger than the sum of its proper divisors (1238084047).

638474751281 is a wasteful number, since it uses less digits than its factorization.

638474751281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107383.

The product of its digits is 9031680, while the sum is 56.

The spelling of 638474751281 in words is "six hundred thirty-eight billion, four hundred seventy-four million, seven hundred fifty-one thousand, two hundred eighty-one".