638634814468 has 96 divisors (see below), whose sum is σ = 1322860609280. Its totient is φ = 264140144640.

The previous prime is 638634814463. The next prime is 638634814487. The reversal of 638634814468 is 864418436836.

It is a happy number.

It is a super-3 number, since 3×638634814468³ (a number of 36 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (61).

It is not an unprimeable number, because it can be changed into a prime (638634814463) 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 31 ways as a sum of consecutive naturals, for example, 24050743 + ... + 24077281.

Almost surely, 2^638634814468 is an apocalyptic number.

It is an amenable number.

638634814468 is an abundant number, since it is smaller than the sum of its proper divisors (684225794812).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638634814468 is a wasteful number, since it uses less digits than its factorization.

638634814468 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26877 (or 26875 counting only the distinct ones).

The product of its digits is 63700992, while the sum is 61.

The spelling of 638634814468 in words is "six hundred thirty-eight billion, six hundred thirty-four million, eight hundred fourteen thousand, four hundred sixty-eight".