638060640 has 192 divisors, whose sum is σ = 2341011456. Its totient is φ = 143050752.

The previous prime is 638060627. The next prime is 638060651. The reversal of 638060640 is 46060836.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 176289 + ... + 179871.

It is an arithmetic number, because the mean of its divisors is an integer number (12192768).

Almost surely, 2^638060640 is an apocalyptic number.

638060640 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 638060640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1170505728).

638060640 is an abundant number, since it is smaller than the sum of its proper divisors (1702950816).

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

638060640 is a wasteful number, since it uses less digits than its factorization.

638060640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3661 (or 3653 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 638060640 is about 25259.8622324034. The cubic root of 638060640 is about 860.9025318597.

The spelling of 638060640 in words is "six hundred thirty-eight million, sixty thousand, six hundred forty".