646440025240 has 32 divisors (see below), whose sum is σ = 1501409093760. Its totient is φ = 250234848000.

The previous prime is 646440025207. The next prime is 646440025249. The reversal of 646440025240 is 42520044646.

646440025240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 646440025240.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646440025249) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 260660061 + ... + 260662540.

It is an arithmetic number, because the mean of its divisors is an integer number (46919034180).

Almost surely, 2^646440025240 is an apocalyptic number.

It is an amenable number.

646440025240 is an abundant number, since it is smaller than the sum of its proper divisors (854969068520).

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

646440025240 is a wasteful number, since it uses less digits than its factorization.

646440025240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521322643 (or 521322639 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 37.

Adding to 646440025240 its reverse (42520044646), we get a palindrome (688960069886).

The spelling of 646440025240 in words is "six hundred forty-six billion, four hundred forty million, twenty-five thousand, two hundred forty".