638977284 has 81 divisors (see below), whose sum is σ = 1780024519. Its totient is φ = 193123920.

The previous prime is 638977253. The next prime is 638977303. The reversal of 638977284 is 482779836.

The square root of 638977284 is 25278.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 638977284.

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1668157 + ... + 1668539.

Almost surely, 2^638977284 is an apocalyptic number.

638977284 is the 25278-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638977284

638977284 is an abundant number, since it is smaller than the sum of its proper divisors (1141047235).

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

638977284 is a wasteful number, since it uses less digits than its factorization.

638977284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 798 (or 399 counting only the distinct ones).

The product of its digits is 4064256, while the sum is 54.

The cubic root of 638977284 is about 861.3145948604.

The spelling of 638977284 in words is "six hundred thirty-eight million, nine hundred seventy-seven thousand, two hundred eighty-four".