638244053225856 has 2880 divisors, whose sum is σ = 2432061723780000. Its totient is φ = 160121932185600.

The previous prime is 638244053225827. The next prime is 638244053225903. The reversal of 638244053225856 is 658522350442836.

638244053225856 is a `hidden beast` number, since 6 + 3 + 8 + 2 + 4 + 40 + 5 + 3 + 2 + 2 + 585 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a junction number, because it is equal to n+sod(n) for n = 638244053225793 and 638244053225802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 359 ways as a sum of consecutive naturals, for example, 4283517135670 + ... + 4283517135818.

Almost surely, 2^{638244053225856} is an apocalyptic number.

638244053225856 is a gapful number since it is divisible by the number (66) 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 638244053225856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1216030861890000).

638244053225856 is an abundant number, since it is smaller than the sum of its proper divisors (1793817670554144).

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

638244053225856 is a wasteful number, since it uses less digits than its factorization.

638244053225856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 371 (or 316 counting only the distinct ones).

The product of its (nonzero) digits is 331776000, while the sum is 63.

The spelling of 638244053225856 in words is "six hundred thirty-eight trillion, two hundred forty-four billion, fifty-three million, two hundred twenty-five thousand, eight hundred fifty-six".