646909646 has 8 divisors (see below), whose sum is σ = 979972344. Its totient is φ = 320252200.

The previous prime is 646909639. The next prime is 646909649.

It is a happy number.

646909646 is nontrivially palindromic in base 10.

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

It is a junction number, because it is equal to n+sod(n) for n = 646909594 and 646909603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646909649) 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, 1601060 + ... + 1601463.

It is an arithmetic number, because the mean of its divisors is an integer number (122496543).

Almost surely, 2^646909646 is an apocalyptic number.

646909646 is a deficient number, since it is larger than the sum of its proper divisors (333062698).

646909646 is a wasteful number, since it uses less digits than its factorization.

646909646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3202626.

The product of its (nonzero) digits is 1679616, while the sum is 50.

The square root of 646909646 is about 25434.4185308019. The cubic root of 646909646 is about 864.8641108774.

The spelling of 646909646 in words is "six hundred forty-six million, nine hundred nine thousand, six hundred forty-six".