638770767840 has 576 divisors, whose sum is σ = 2355851796480. Its totient is φ = 157146992640.

The previous prime is 638770767839. The next prime is 638770767853. The reversal of 638770767840 is 48767077836.

638770767840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 368591614 + ... + 368593346.

It is an arithmetic number, because the mean of its divisors is an integer number (4090020480).

Almost surely, 2^638770767840 is an apocalyptic number.

638770767840 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 638770767840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1177925898240).

638770767840 is an abundant number, since it is smaller than the sum of its proper divisors (1717081028640).

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

638770767840 is a wasteful number, since it uses less digits than its factorization.

638770767840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2167 (or 2156 counting only the distinct ones).

The product of its (nonzero) digits is 66382848, while the sum is 63.

The spelling of 638770767840 in words is "six hundred thirty-eight billion, seven hundred seventy million, seven hundred sixty-seven thousand, eight hundred forty".