638412347520 has 640 divisors, whose sum is σ = 2368716134400. Its totient is φ = 163661783040.

The previous prime is 638412347513. The next prime is 638412347533. The reversal of 638412347520 is 25743214836.

638412347520 is a `hidden beast` number, since 6 + 3 + 84 + 1 + 2 + 3 + 47 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 407409777 + ... + 407411343.

It is an arithmetic number, because the mean of its divisors is an integer number (3701118960).

Almost surely, 2^638412347520 is an apocalyptic number.

638412347520 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 638412347520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1184358067200).

638412347520 is an abundant number, since it is smaller than the sum of its proper divisors (1730303786880).

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

638412347520 is a wasteful number, since it uses less digits than its factorization.

638412347520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1898 (or 1877 counting only the distinct ones).

The product of its (nonzero) digits is 967680, while the sum is 45.

The spelling of 638412347520 in words is "six hundred thirty-eight billion, four hundred twelve million, three hundred forty-seven thousand, five hundred twenty".