647905890 has 128 divisors (see below), whose sum is σ = 1737031680. Its totient is φ = 153964800.

The previous prime is 647905889. The next prime is 647905961. The reversal of 647905890 is 98509746.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 653295 + ... + 654285.

It is an arithmetic number, because the mean of its divisors is an integer number (13570560).

Almost surely, 2^647905890 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 647905890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (868515840).

647905890 is an abundant number, since it is smaller than the sum of its proper divisors (1089125790).

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

647905890 is a wasteful number, since it uses less digits than its factorization.

647905890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1088.

The product of its (nonzero) digits is 544320, while the sum is 48.

The square root of 647905890 is about 25453.9955606188. The cubic root of 647905890 is about 865.3078481479.

The spelling of 647905890 in words is "six hundred forty-seven million, nine hundred five thousand, eight hundred ninety".