638547876436 has 6 divisors (see below), whose sum is σ = 1117458783770. Its totient is φ = 319273938216.

The previous prime is 638547876431. The next prime is 638547876467. The reversal of 638547876436 is 634678745836.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 638471313936 + 76562500 = 799044^2 + 8750^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638547876431) 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 as a sum of consecutive naturals, namely, 79818484551 + ... + 79818484558.

Almost surely, 2^638547876436 is an apocalyptic number.

It is an amenable number.

638547876436 is a deficient number, since it is larger than the sum of its proper divisors (478910907334).

638547876436 is a wasteful number, since it uses less digits than its factorization.

638547876436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159636969113 (or 159636969111 counting only the distinct ones).

The product of its digits is 487710720, while the sum is 67.

The spelling of 638547876436 in words is "six hundred thirty-eight billion, five hundred forty-seven million, eight hundred seventy-six thousand, four hundred thirty-six".