644184481446 has 32 divisors (see below), whose sum is σ = 1561659350400. Its totient is φ = 195207418440.

The previous prime is 644184481427. The next prime is 644184481463.

644184481446 is a `hidden beast` number, since 6 + 4 + 41 + 84 + 4 + 81 + 446 = 666.

644184481446 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×644184481446² (a number of 24 digits) contains 22 as substring.

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

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 644184481392 and 644184481401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 542242236 + ... + 542243423.

It is an arithmetic number, because the mean of its divisors is an integer number (48801854700).

Almost surely, 2^644184481446 is an apocalyptic number.

644184481446 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

644184481446 is an abundant number, since it is smaller than the sum of its proper divisors (917474868954).

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

644184481446 is a wasteful number, since it uses less digits than its factorization.

644184481446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1084485681 (or 1084485675 counting only the distinct ones).

The product of its digits is 9437184, while the sum is 54.

The spelling of 644184481446 in words is "six hundred forty-four billion, one hundred eighty-four million, four hundred eighty-one thousand, four hundred forty-six".