647767973 has 4 divisors (see below), whose sum is σ = 648965868. Its totient is φ = 646570080.

The previous prime is 647767963. The next prime is 647768029. The reversal of 647767973 is 379767746.

647767973 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, and also an emirpimes, since its reverse is a distinct semiprime: 379767746 = 2 ⋅189883873.

It can be written as a sum of positive squares in 2 ways, for example, as 503239489 + 144528484 = 22433^2 + 12022^2 .

It is a cyclic number.

It is not a de Polignac number, because 647767973 - 2⁴ = 647767957 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647767933) 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, 598136 + ... + 599217.

It is an arithmetic number, because the mean of its divisors is an integer number (162241467).

Almost surely, 2^647767973 is an apocalyptic number.

It is an amenable number.

647767973 is a deficient number, since it is larger than the sum of its proper divisors (1197895).

647767973 is a wasteful number, since it uses less digits than its factorization.

647767973 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1197894.

The product of its digits is 9335088, while the sum is 56.

The square root of 647767973 is about 25451.2862739784. The cubic root of 647767973 is about 865.2464456443.

The spelling of 647767973 in words is "six hundred forty-seven million, seven hundred sixty-seven thousand, nine hundred seventy-three".