646810406 has 16 divisors (see below), whose sum is σ = 1064916288. Its totient is φ = 292199400.

The previous prime is 646810379. The next prime is 646810427. The reversal of 646810406 is 604018646.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 86600 + ... + 93771.

It is an arithmetic number, because the mean of its divisors is an integer number (66557268).

Almost surely, 2^646810406 is an apocalyptic number.

646810406 is a deficient number, since it is larger than the sum of its proper divisors (418105882).

646810406 is a wasteful number, since it uses less digits than its factorization.

646810406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180547.

The product of its (nonzero) digits is 27648, while the sum is 35.

The square root of 646810406 is about 25432.4675562557. The cubic root of 646810406 is about 864.8198834214.

The spelling of 646810406 in words is "six hundred forty-six million, eight hundred ten thousand, four hundred six".