647345761 has 4 divisors (see below), whose sum is σ = 663134724. Its totient is φ = 631556800.

The previous prime is 647345753. The next prime is 647345767. The reversal of 647345761 is 167543746.

647345761 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 350438400 + 296907361 = 18720^2 + 17231^2 .

It is a cyclic number.

It is not a de Polignac number, because 647345761 - 2³ = 647345753 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647345767) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7894420 + ... + 7894501.

It is an arithmetic number, because the mean of its divisors is an integer number (165783681).

Almost surely, 2^647345761 is an apocalyptic number.

It is an amenable number.

647345761 is a deficient number, since it is larger than the sum of its proper divisors (15788963).

647345761 is a wasteful number, since it uses less digits than its factorization.

647345761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15788962.

The product of its digits is 423360, while the sum is 43.

The square root of 647345761 is about 25442.9904099341. The cubic root of 647345761 is about 865.0584169843.

The spelling of 647345761 in words is "six hundred forty-seven million, three hundred forty-five thousand, seven hundred sixty-one".