646398947 has 8 divisors (see below), whose sum is σ = 649732752. Its totient is φ = 643072000.

The previous prime is 646398911. The next prime is 646398983. The reversal of 646398947 is 749893646.

646398947 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (646398911) and next prime (646398983).

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

It is a cyclic number.

It is not a de Polignac number, because 646398947 - 2²⁴ = 629621731 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 646398892 and 646398901.

It is not an unprimeable number, because it can be changed into a prime (646398997) 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, 402947 + ... + 404547.

It is an arithmetic number, because the mean of its divisors is an integer number (81216594).

Almost surely, 2^646398947 is an apocalyptic number.

646398947 is a deficient number, since it is larger than the sum of its proper divisors (3333805).

646398947 is a wasteful number, since it uses less digits than its factorization.

646398947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3429.

The product of its digits is 7838208, while the sum is 56.

The square root of 646398947 is about 25424.3770228495. The cubic root of 646398947 is about 864.6364636735.

The spelling of 646398947 in words is "six hundred forty-six million, three hundred ninety-eight thousand, nine hundred forty-seven".