647665553 has 4 divisors (see below), whose sum is σ = 649708980. Its totient is φ = 645622128.

The previous prime is 647665537. The next prime is 647665607. The reversal of 647665553 is 355566746.

647665553 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 335365969 + 312299584 = 18313^2 + 17672^2 .

It is a cyclic number.

It is not a de Polignac number, because 647665553 - 2⁴ = 647665537 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 647665498 and 647665507.

It is not an unprimeable number, because it can be changed into a prime (647665153) 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, 1021238 + ... + 1021871.

It is an arithmetic number, because the mean of its divisors is an integer number (162427245).

Almost surely, 2^647665553 is an apocalyptic number.

It is an amenable number.

647665553 is a deficient number, since it is larger than the sum of its proper divisors (2043427).

647665553 is a wasteful number, since it uses less digits than its factorization.

647665553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2043426.

The product of its digits is 2268000, while the sum is 47.

The square root of 647665553 is about 25449.2741153849. The cubic root of 647665553 is about 865.2008412429.

The spelling of 647665553 in words is "six hundred forty-seven million, six hundred sixty-five thousand, five hundred fifty-three".