647661390 has 16 divisors (see below), whose sum is σ = 1554387408. Its totient is φ = 172709696.

The previous prime is 647661373. The next prime is 647661403. The reversal of 647661390 is 93166746.

647661390 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, 10794327 + ... + 10794386.

It is an arithmetic number, because the mean of its divisors is an integer number (97149213).

Almost surely, 2^647661390 is an apocalyptic number.

647661390 is an abundant number, since it is smaller than the sum of its proper divisors (906726018).

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

647661390 is a wasteful number, since it uses less digits than its factorization.

647661390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21588723.

The product of its (nonzero) digits is 163296, while the sum is 42.

The square root of 647661390 is about 25449.1923251014. The cubic root of 647661390 is about 865.1989874884.

The spelling of 647661390 in words is "six hundred forty-seven million, six hundred sixty-one thousand, three hundred ninety".