644543122 has 12 divisors (see below), whose sum is σ = 1010679390. Its totient is φ = 308259248.

The previous prime is 644543113. The next prime is 644543147. The reversal of 644543122 is 221345446.

644543122 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 416200801 + 228342321 = 20401^2 + 15111^2 .

It is a super-2 number, since 2×644543122² = 830871672235013768, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 303547 + ... + 305662.

Almost surely, 2^644543122 is an apocalyptic number.

644543122 is a deficient number, since it is larger than the sum of its proper divisors (366136268).

644543122 is a wasteful number, since it uses less digits than its factorization.

644543122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 609257 (or 609234 counting only the distinct ones).

The product of its digits is 23040, while the sum is 31.

The square root of 644543122 is about 25387.8538281596. The cubic root of 644543122 is about 863.8082073500.

Adding to 644543122 its reverse (221345446), we get a palindrome (865888568).

It can be divided in two parts, 64454 and 3122, that added together give a palindrome (67576).

The spelling of 644543122 in words is "six hundred forty-four million, five hundred forty-three thousand, one hundred twenty-two".