647257338 has 128 divisors (see below), whose sum is σ = 1788272640. Its totient is φ = 168972480.

The previous prime is 647257307. The next prime is 647257343. The reversal of 647257338 is 833752746.

647257338 is a `hidden beast` number, since 6 + 4 + 72 + 573 + 3 + 8 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 647257293 and 647257302.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 525183 + ... + 526413.

It is an arithmetic number, because the mean of its divisors is an integer number (13970880).

Almost surely, 2^647257338 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 647257338, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (894136320).

647257338 is an abundant number, since it is smaller than the sum of its proper divisors (1141015302).

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

647257338 is a wasteful number, since it uses less digits than its factorization.

647257338 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1369 (or 1363 counting only the distinct ones).

The product of its digits is 846720, while the sum is 45.

The square root of 647257338 is about 25441.2526814227. The cubic root of 647257338 is about 865.0190281713.

The spelling of 647257338 in words is "six hundred forty-seven million, two hundred fifty-seven thousand, three hundred thirty-eight".