646404216 has 16 divisors (see below), whose sum is σ = 1616010600. Its totient is φ = 215468064.

The previous prime is 646404203. The next prime is 646404247. The reversal of 646404216 is 612404646.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13466731 + ... + 13466778.

Almost surely, 2^646404216 is an apocalyptic number.

It is an amenable number.

646404216 is an abundant number, since it is smaller than the sum of its proper divisors (969606384).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646404216 is a wasteful number, since it uses less digits than its factorization.

646404216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26933518 (or 26933514 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 33.

The square root of 646404216 is about 25424.4806436631. The cubic root of 646404216 is about 864.6388129745.

The spelling of 646404216 in words is "six hundred forty-six million, four hundred four thousand, two hundred sixteen".