646240032 has 144 divisors (see below), whose sum is σ = 1953256032. Its totient is φ = 210055680.

The previous prime is 646240009. The next prime is 646240033. The reversal of 646240032 is 230042646.

646240032 is a `hidden beast` number, since 6 + 4 + 624 + 0 + 0 + 32 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a super-2 number, since 2×646240032² = 835252357918722048, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 646239978 and 646240005.

It is not an unprimeable number, because it can be changed into a prime (646240033) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 317803 + ... + 319829.

It is an arithmetic number, because the mean of its divisors is an integer number (13564278).

Almost surely, 2^646240032 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 646240032, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (976628016).

646240032 is an abundant number, since it is smaller than the sum of its proper divisors (1307016000).

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

646240032 is a wasteful number, since it uses less digits than its factorization.

646240032 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2093 (or 2073 counting only the distinct ones).

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

The square root of 646240032 is about 25421.2515820917. The cubic root of 646240032 is about 864.5656018804.

Adding to 646240032 its reverse (230042646), we get a palindrome (876282678).

The spelling of 646240032 in words is "six hundred forty-six million, two hundred forty thousand, thirty-two".