644246004006 has 24 divisors (see below), whose sum is σ = 1522763282664. Its totient is φ = 195226061760.

The previous prime is 644246003969. The next prime is 644246004029. The reversal of 644246004006 is 600400642446.

It is a happy number.

644246004006 is a `hidden beast` number, since 6 + 4 + 4 + 2 + 4 + 600 + 40 + 0 + 6 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1626883651 + ... + 1626884046.

It is an arithmetic number, because the mean of its divisors is an integer number (63448470111).

Almost surely, 2^644246004006 is an apocalyptic number.

644246004006 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

644246004006 is an abundant number, since it is smaller than the sum of its proper divisors (878517278658).

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

644246004006 is a wasteful number, since it uses less digits than its factorization.

644246004006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3253767716 (or 3253767713 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 36.

The spelling of 644246004006 in words is "six hundred forty-four billion, two hundred forty-six million, four thousand, six".