647391798 has 16 divisors (see below), whose sum is σ = 1438648560. Its totient is φ = 215797248.

The previous prime is 647391761. The next prime is 647391839. The reversal of 647391798 is 897193746.

It is a happy number.

647391798 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×647391798² = 838232280235345608, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 11988737 = 647391798 / (6 + 4 + 7 + 3 + 9 + 1 + 7 + 9 + 8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5994315 + ... + 5994422.

It is an arithmetic number, because the mean of its divisors is an integer number (89915535).

Almost surely, 2^647391798 is an apocalyptic number.

647391798 is an abundant number, since it is smaller than the sum of its proper divisors (791256762).

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

647391798 is a wasteful number, since it uses less digits than its factorization.

647391798 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11988748 (or 11988742 counting only the distinct ones).

The product of its digits is 2286144, while the sum is 54.

The square root of 647391798 is about 25443.8951027550. The cubic root of 647391798 is about 865.0789231562.

The spelling of 647391798 in words is "six hundred forty-seven million, three hundred ninety-one thousand, seven hundred ninety-eight".