646989648 has 80 divisors (see below), whose sum is σ = 1700891136. Its totient is φ = 211888000.

The previous prime is 646989647. The next prime is 646989667. The reversal of 646989648 is 846989646.

It is a junction number, because it is equal to n+sod(n) for n = 646989591 and 646989600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646989641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 999661 + ... + 1000307.

Almost surely, 2^646989648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646989648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (850445568).

646989648 is an abundant number, since it is smaller than the sum of its proper divisors (1053901488).

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

646989648 is a wasteful number, since it uses less digits than its factorization.

646989648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 992 (or 986 counting only the distinct ones).

The product of its digits is 17915904, while the sum is 60.

The square root of 646989648 is about 25435.9911935824. The cubic root of 646989648 is about 864.8997614029.

The spelling of 646989648 in words is "six hundred forty-six million, nine hundred eighty-nine thousand, six hundred forty-eight".