646291444644 has 120 divisors (see below), whose sum is σ = 1773810709440. Its totient is φ = 204799358016.

The previous prime is 646291444639. The next prime is 646291444649. The reversal of 646291444644 is 446444192646.

646291444644 is a `hidden beast` number, since 6 + 4 + 629 + 1 + 4 + 4 + 4 + 6 + 4 + 4 = 666.

It is an interprime number because it is at equal distance from previous prime (646291444639) and next prime (646291444649).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (646291444649) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 948642 + ... + 1480710.

It is an arithmetic number, because the mean of its divisors is an integer number (14781755912).

Almost surely, 2^646291444644 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 646291444644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (886905354720).

646291444644 is an abundant number, since it is smaller than the sum of its proper divisors (1127519264796).

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

646291444644 is a wasteful number, since it uses less digits than its factorization.

646291444644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 532271 (or 532260 counting only the distinct ones).

The product of its digits is 15925248, while the sum is 54.

The spelling of 646291444644 in words is "six hundred forty-six billion, two hundred ninety-one million, four hundred forty-four thousand, six hundred forty-four".