638443673047 has 4 divisors (see below), whose sum is σ = 638511164136. Its totient is φ = 638376181960.

The previous prime is 638443673027. The next prime is 638443673081. The reversal of 638443673047 is 740376344836.

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

It is a cyclic number.

It is not a de Polignac number, because 638443673047 - 2¹⁵ = 638443640279 is a prime.

It is a super-2 number, since 2×638443673047² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638443673027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33731353 + ... + 33750274.

It is an arithmetic number, because the mean of its divisors is an integer number (159627791034).

Almost surely, 2^638443673047 is an apocalyptic number.

638443673047 is a deficient number, since it is larger than the sum of its proper divisors (67491089).

638443673047 is an equidigital number, since it uses as much as digits as its factorization.

638443673047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67491088.

The product of its (nonzero) digits is 24385536, while the sum is 55.

The spelling of 638443673047 in words is "six hundred thirty-eight billion, four hundred forty-three million, six hundred seventy-three thousand, forty-seven".