646032240 has 160 divisors (see below), whose sum is σ = 2543170560. Its totient is φ = 147661056.

The previous prime is 646032227. The next prime is 646032251. The reversal of 646032240 is 42230646.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6244 + ... + 36483.

It is an arithmetic number, because the mean of its divisors is an integer number (15894816).

Almost surely, 2^646032240 is an apocalyptic number.

646032240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646032240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1271585280).

646032240 is an abundant number, since it is smaller than the sum of its proper divisors (1897138320).

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

646032240 is a wasteful number, since it uses less digits than its factorization.

646032240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42756 (or 42744 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 646032240 is about 25417.1642792818. The cubic root of 646032240 is about 864.4729278146.

Adding to 646032240 its reverse (42230646), we get a palindrome (688262886).

The spelling of 646032240 in words is "six hundred forty-six million, thirty-two thousand, two hundred forty".