644364207774 has 48 divisors (see below), whose sum is σ = 1595618650080. Its totient is φ = 184098274560.

The previous prime is 644364207763. The next prime is 644364207779. The reversal of 644364207774 is 477702463446.

644364207774 is a `hidden beast` number, since 6 + 4 + 4 + 364 + 207 + 7 + 74 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 644364207774.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644364207779) 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, 5450362 + ... + 5567330.

It is an arithmetic number, because the mean of its divisors is an integer number (33242055210).

Almost surely, 2^644364207774 is an apocalyptic number.

644364207774 is an abundant number, since it is smaller than the sum of its proper divisors (951254442306).

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

644364207774 is a wasteful number, since it uses less digits than its factorization.

644364207774 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160705 (or 160702 counting only the distinct ones).

The product of its (nonzero) digits is 18966528, while the sum is 54.

The spelling of 644364207774 in words is "six hundred forty-four billion, three hundred sixty-four million, two hundred seven thousand, seven hundred seventy-four".