647873641 has 4 divisors (see below), whose sum is σ = 648146772. Its totient is φ = 647600512.

The previous prime is 647873627. The next prime is 647873657. The reversal of 647873641 is 146378746.

647873641 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 139145616 + 508728025 = 11796^2 + 22555^2 .

It is a cyclic number.

It is not a de Polignac number, because 647873641 - 2¹¹ = 647871593 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 647873591 and 647873600.

It is not an unprimeable number, because it can be changed into a prime (647873141) 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, 132976 + ... + 137761.

It is an arithmetic number, because the mean of its divisors is an integer number (162036693).

Almost surely, 2^647873641 is an apocalyptic number.

It is an amenable number.

647873641 is a deficient number, since it is larger than the sum of its proper divisors (273131).

647873641 is a wasteful number, since it uses less digits than its factorization.

647873641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273130.

The product of its digits is 677376, while the sum is 46.

The square root of 647873641 is about 25453.3620765509. The cubic root of 647873641 is about 865.2934912399.

The spelling of 647873641 in words is "six hundred forty-seven million, eight hundred seventy-three thousand, six hundred forty-one".