647922657 has 4 divisors (see below), whose sum is σ = 863896880. Its totient is φ = 431948436.

The previous prime is 647922643. The next prime is 647922733. The reversal of 647922657 is 756229746.

647922657 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 a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 647922657 - 2¹⁰ = 647921633 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (647922607) 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, 107987107 + ... + 107987112.

It is an arithmetic number, because the mean of its divisors is an integer number (215974220).

Almost surely, 2^647922657 is an apocalyptic number.

It is an amenable number.

647922657 is a deficient number, since it is larger than the sum of its proper divisors (215974223).

647922657 is a wasteful number, since it uses less digits than its factorization.

647922657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215974222.

The product of its digits is 1270080, while the sum is 48.

The square root of 647922657 is about 25454.3249173888. The cubic root of 647922657 is about 865.3153124478.

The spelling of 647922657 in words is "six hundred forty-seven million, nine hundred twenty-two thousand, six hundred fifty-seven".