638674452180 has 60 divisors (see below), whose sum is σ = 2003545416180. Its totient is φ = 170313186816.

The previous prime is 638674452167. The next prime is 638674452253. The reversal of 638674452180 is 81254476836.

It is a happy number.

638674452180 is a `hidden beast` number, since 6 + 3 + 8 + 6 + 7 + 4 + 452 + 180 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 163253170116 + 475421282064 = 404046^2 + 689508^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 197120125 + ... + 197123364.

It is an arithmetic number, because the mean of its divisors is an integer number (33392423603).

Almost surely, 2^638674452180 is an apocalyptic number.

638674452180 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

638674452180 is an abundant number, since it is smaller than the sum of its proper divisors (1364870964000).

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

638674452180 is a wasteful number, since it uses less digits than its factorization.

638674452180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394243510 (or 394243499 counting only the distinct ones).

The product of its (nonzero) digits is 7741440, while the sum is 54.

The spelling of 638674452180 in words is "six hundred thirty-eight billion, six hundred seventy-four million, four hundred fifty-two thousand, one hundred eighty".