638046864 has 480 divisors, whose sum is σ = 2404846080. Its totient is φ = 153280512.

The previous prime is 638046853. The next prime is 638046881. The reversal of 638046864 is 468640836.

638046864 is a `hidden beast` number, since 638 + 0 + 4 + 6 + 8 + 6 + 4 = 666.

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, 8740332 + ... + 8740404.

It is an arithmetic number, because the mean of its divisors is an integer number (5010096).

Almost surely, 2^638046864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638046864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1202423040).

638046864 is an abundant number, since it is smaller than the sum of its proper divisors (1766799216).

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

638046864 is a wasteful number, since it uses less digits than its factorization.

638046864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159 (or 150 counting only the distinct ones).

The product of its (nonzero) digits is 663552, while the sum is 45.

The square root of 638046864 is about 25259.5895453588. The cubic root of 638046864 is about 860.8963360648.

The spelling of 638046864 in words is "six hundred thirty-eight million, forty-six thousand, eight hundred sixty-four".