647647121 has 8 divisors (see below), whose sum is σ = 719855424. Its totient is φ = 577660720.

The previous prime is 647647109. The next prime is 647647163. The reversal of 647647121 is 121746746.

It is a happy number.

647647121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647647121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647647171) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 554861 + ... + 556026.

It is an arithmetic number, because the mean of its divisors is an integer number (89981928).

Almost surely, 2^647647121 is an apocalyptic number.

It is an amenable number.

647647121 is a deficient number, since it is larger than the sum of its proper divisors (72208303).

647647121 is a wasteful number, since it uses less digits than its factorization.

647647121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1110951.

The product of its digits is 56448, while the sum is 38.

The square root of 647647121 is about 25448.9119806722. The cubic root of 647647121 is about 865.1926335431.

The spelling of 647647121 in words is "six hundred forty-seven million, six hundred forty-seven thousand, one hundred twenty-one".