638688434973 has 8 divisors (see below), whose sum is σ = 880949565600. Its totient is φ = 411109797168.

The previous prime is 638688434959. The next prime is 638688434983. The reversal of 638688434973 is 379434886836.

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

It is not a de Polignac number, because 638688434973 - 2²⁵ = 638654880541 is a prime.

It is a super-4 number, since 4×638688434973⁴ (a number of 48 digits) contains 4444 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 638688434898 and 638688434907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638688434983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3670623103 + ... + 3670623276.

It is an arithmetic number, because the mean of its divisors is an integer number (110118695700).

Almost surely, 2^638688434973 is an apocalyptic number.

It is an amenable number.

638688434973 is a deficient number, since it is larger than the sum of its proper divisors (242261130627).

638688434973 is a wasteful number, since it uses less digits than its factorization.

638688434973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7341246411.

The product of its digits is 501645312, while the sum is 69.

The spelling of 638688434973 in words is "six hundred thirty-eight billion, six hundred eighty-eight million, four hundred thirty-four thousand, nine hundred seventy-three".