646493856 has 48 divisors (see below), whose sum is σ = 1701421344. Its totient is φ = 214942464.

The previous prime is 646493849. The next prime is 646493879. The reversal of 646493856 is 658394646.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a junction number, because it is equal to n+sod(n) for n = 646493799 and 646493808.

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, 29631 + ... + 46593.

It is an arithmetic number, because the mean of its divisors is an integer number (35446278).

Almost surely, 2^646493856 is an apocalyptic number.

It is an amenable number.

646493856 is an abundant number, since it is smaller than the sum of its proper divisors (1054927488).

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

646493856 is a wasteful number, since it uses less digits than its factorization.

646493856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17373 (or 17365 counting only the distinct ones).

The product of its digits is 3732480, while the sum is 51.

The square root of 646493856 is about 25426.2434504195. The cubic root of 646493856 is about 864.6787790096.

The spelling of 646493856 in words is "six hundred forty-six million, four hundred ninety-three thousand, eight hundred fifty-six".