646306240 has 28 divisors (see below), whose sum is σ = 1539017496. Its totient is φ = 258522368.

The previous prime is 646306183. The next prime is 646306277. The reversal of 646306240 is 42603646.

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 3 ways as a sum of consecutive naturals, for example, 1009534 + ... + 1010173.

Almost surely, 2^646306240 is an apocalyptic number.

It is an amenable number.

646306240 is an abundant number, since it is smaller than the sum of its proper divisors (892711256).

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

646306240 is a wasteful number, since it uses less digits than its factorization.

646306240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2019724 (or 2019714 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 31.

The square root of 646306240 is about 25422.5537662919. The cubic root of 646306240 is about 864.5951261036.

Adding to 646306240 its reverse (42603646), we get a palindrome (688909886).

The spelling of 646306240 in words is "six hundred forty-six million, three hundred six thousand, two hundred forty".