644354464453446 has 32 divisors (see below), whose sum is σ = 1332621567756288. Its totient is φ = 207587019800160.

The previous prime is 644354464453421. The next prime is 644354464453451.

644354464453446 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×644354464453446² (a number of 30 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (66) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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, 15121410790 + ... + 15121453401.

It is an arithmetic number, because the mean of its divisors is an integer number (41644423992384).

Almost surely, 2^{644354464453446} is an apocalyptic number.

644354464453446 is an abundant number, since it is smaller than the sum of its proper divisors (688267103302842).

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

644354464453446 is a wasteful number, since it uses less digits than its factorization.

644354464453446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30242864316.

The product of its digits is 3185049600, while the sum is 66.

The spelling of 644354464453446 in words is "six hundred forty-four trillion, three hundred fifty-four billion, four hundred sixty-four million, four hundred fifty-three thousand, four hundred forty-six".