646841984 has 32 divisors (see below), whose sum is σ = 1333073700. Its totient is φ = 312266752.

The previous prime is 646841981. The next prime is 646841989. The reversal of 646841984 is 489148646.

It can be written as a sum of positive squares in 2 ways, for example, as 637057600 + 9784384 = 25240^2 + 3128^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (646841981) 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, 83417 + ... + 90840.

Almost surely, 2^646841984 is an apocalyptic number.

646841984 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

646841984 is an abundant number, since it is smaller than the sum of its proper divisors (686231716).

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

646841984 is a wasteful number, since it uses less digits than its factorization.

646841984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174300 (or 174288 counting only the distinct ones).

The product of its digits is 1327104, while the sum is 50.

The square root of 646841984 is about 25433.0883692878. The cubic root of 646841984 is about 864.8339570137.

The spelling of 646841984 in words is "six hundred forty-six million, eight hundred forty-one thousand, nine hundred eighty-four".