638406247086 has 256 divisors, whose sum is σ = 1567044403200. Its totient is φ = 194288531040.

The previous prime is 638406247049. The next prime is 638406247099. The reversal of 638406247086 is 680742604836.

638406247086 is a `hidden beast` number, since 6 + 3 + 8 + 4 + 0 + 624 + 7 + 0 + 8 + 6 = 666.

638406247086 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 127 ways as a sum of consecutive naturals, for example, 986717215 + ... + 986717861.

It is an arithmetic number, because the mean of its divisors is an integer number (6121267200).

Almost surely, 2^638406247086 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638406247086, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (783522201600).

638406247086 is an abundant number, since it is smaller than the sum of its proper divisors (928638156114).

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

638406247086 is a wasteful number, since it uses less digits than its factorization.

638406247086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1103 (or 1085 counting only the distinct ones).

The product of its (nonzero) digits is 9289728, while the sum is 54.

The spelling of 638406247086 in words is "six hundred thirty-eight billion, four hundred six million, two hundred forty-seven thousand, eighty-six".