638780525460 has 384 divisors, whose sum is σ = 2484653875200. Its totient is φ = 132360791040.

The previous prime is 638780525417. The next prime is 638780525477. The reversal of 638780525460 is 64525087836.

638780525460 is a `hidden beast` number, since 6 + 3 + 8 + 78 + 0 + 525 + 46 + 0 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 638780525397 and 638780525406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 14905824 + ... + 14948616.

It is an arithmetic number, because the mean of its divisors is an integer number (6470452800).

Almost surely, 2^638780525460 is an apocalyptic number.

638780525460 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 638780525460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1242326937600).

638780525460 is an abundant number, since it is smaller than the sum of its proper divisors (1845873349740).

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

638780525460 is a wasteful number, since it uses less digits than its factorization.

638780525460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43188 (or 43180 counting only the distinct ones).

The product of its (nonzero) digits is 9676800, while the sum is 54.

The spelling of 638780525460 in words is "six hundred thirty-eight billion, seven hundred eighty million, five hundred twenty-five thousand, four hundred sixty".