638249299742880 has 2304 divisors, whose sum is σ = 2858495754240000. Its totient is φ = 133746948679680.

The previous prime is 638249299742867. The next prime is 638249299742947. The reversal of 638249299742880 is 88247992942836.

638249299742880 is a `hidden beast` number, since 6 + 3 + 8 + 2 + 4 + 9 + 29 + 97 + 428 + 80 = 666.

It is a super-2 number, since 2×638249299742880² (a number of 30 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a self number, because there is not a number n which added to its sum of digits gives 638249299742880.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 10099009521 + ... + 10099072719.

It is an arithmetic number, because the mean of its divisors is an integer number (1240666560000).

Almost surely, 2^{638249299742880} is an apocalyptic number.

638249299742880 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638249299742880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1429247877120000).

638249299742880 is an abundant number, since it is smaller than the sum of its proper divisors (2220246454497120).

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

638249299742880 is a wasteful number, since it uses less digits than its factorization.

638249299742880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63299 (or 63266 counting only the distinct ones).

The product of its (nonzero) digits is 6019743744, while the sum is 81.

The spelling of 638249299742880 in words is "six hundred thirty-eight trillion, two hundred forty-nine billion, two hundred ninety-nine million, seven hundred forty-two thousand, eight hundred eighty".