646917406 has 12 divisors (see below), whose sum is σ = 974944872. Its totient is φ = 321938264.

The previous prime is 646917391. The next prime is 646917407. The reversal of 646917406 is 604719646.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646917407) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 582780 + ... + 583888.

It is an arithmetic number, because the mean of its divisors is an integer number (81245406).

Almost surely, 2^646917406 is an apocalyptic number.

646917406 is a deficient number, since it is larger than the sum of its proper divisors (328027466).

646917406 is an equidigital number, since it uses as much as digits as its factorization.

646917406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2483 (or 1374 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 43.

The square root of 646917406 is about 25434.5710795366. The cubic root of 646917406 is about 864.8675690206.

The spelling of 646917406 in words is "six hundred forty-six million, nine hundred seventeen thousand, four hundred six".