647261649 has 12 divisors (see below), whose sum is σ = 935427636. Its totient is φ = 431279712.

The previous prime is 647261633. The next prime is 647261663. The reversal of 647261649 is 946162746.

647261649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 117939600 + 529322049 = 10860^2 + 23007^2 .

It is not a de Polignac number, because 647261649 - 2⁴ = 647261633 is a prime.

It is a super-3 number, since 3×647261649³ (a number of 27 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (647261669) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34 + ... + 35979.

It is an arithmetic number, because the mean of its divisors is an integer number (77952303).

Almost surely, 2^647261649 is an apocalyptic number.

It is an amenable number.

647261649 is a deficient number, since it is larger than the sum of its proper divisors (288165987).

647261649 is a wasteful number, since it uses less digits than its factorization.

647261649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38016 (or 38013 counting only the distinct ones).

The product of its digits is 435456, while the sum is 45.

The square root of 647261649 is about 25441.3374058834. The cubic root of 647261649 is about 865.0209486278.

It can be divided in two parts, 6472 and 61649, that added together give a square (68121 = 261²).

The spelling of 647261649 in words is "six hundred forty-seven million, two hundred sixty-one thousand, six hundred forty-nine".