638884454421 has 8 divisors (see below), whose sum is σ = 857974327840. Its totient is φ = 422858775312.

The previous prime is 638884454413. The next prime is 638884454459. The reversal of 638884454421 is 124454488836.

It is a happy number.

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

It is not a de Polignac number, because 638884454421 - 2³ = 638884454413 is a prime.

It is a super-2 number, since 2×638884454421² (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 (638884454401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 766048090 + ... + 766048923.

It is an arithmetic number, because the mean of its divisors is an integer number (107246790980).

Almost surely, 2^638884454421 is an apocalyptic number.

It is an amenable number.

638884454421 is a deficient number, since it is larger than the sum of its proper divisors (219089873419).

638884454421 is a wasteful number, since it uses less digits than its factorization.

638884454421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1532097155.

The product of its digits is 23592960, while the sum is 57.

The spelling of 638884454421 in words is "six hundred thirty-eight billion, eight hundred eighty-four million, four hundred fifty-four thousand, four hundred twenty-one".