646047640 has 64 divisors (see below), whose sum is σ = 1689465600. Its totient is φ = 217742208.

The previous prime is 646047629. The next prime is 646047641. The reversal of 646047640 is 46740646.

It is a self number, because there is not a number n which added to its sum of digits gives 646047640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646047641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3034 + ... + 36073.

It is an arithmetic number, because the mean of its divisors is an integer number (26397900).

Almost surely, 2^646047640 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 646047640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (844732800).

646047640 is an abundant number, since it is smaller than the sum of its proper divisors (1043417960).

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

646047640 is a wasteful number, since it uses less digits than its factorization.

646047640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39184 (or 39180 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 37.

The square root of 646047640 is about 25417.4672223650. The cubic root of 646047640 is about 864.4797968099.

The spelling of 646047640 in words is "six hundred forty-six million, forty-seven thousand, six hundred forty".