644463364446 has 32 divisors (see below), whose sum is σ = 1562335430400. Its totient is φ = 195291928440.

The previous prime is 644463364403. The next prime is 644463364469.

644463364446 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×644463364446² (a number of 24 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

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

It is a junction number, because it is equal to n+sod(n) for n = 644463364392 and 644463364401.

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, 542476986 + ... + 542478173.

It is an arithmetic number, because the mean of its divisors is an integer number (48822982200).

Almost surely, 2^644463364446 is an apocalyptic number.

644463364446 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

644463364446 is an abundant number, since it is smaller than the sum of its proper divisors (917872065954).

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

644463364446 is a wasteful number, since it uses less digits than its factorization.

644463364446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1084955181 (or 1084955175 counting only the distinct ones).

The product of its digits is 47775744, while the sum is 54.

The spelling of 644463364446 in words is "six hundred forty-four billion, four hundred sixty-three million, three hundred sixty-four thousand, four hundred forty-six".