644435141 has 16 divisors (see below), whose sum is σ = 782390400. Its totient is φ = 518488128.

The previous prime is 644435093. The next prime is 644435147. The reversal of 644435141 is 141534446.

It is a cyclic number.

It is not a de Polignac number, because 644435141 - 2¹⁴ = 644418757 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 644435098 and 644435107.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644435147) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7730 + ... + 36723.

It is an arithmetic number, because the mean of its divisors is an integer number (48899400).

Almost surely, 2^644435141 is an apocalyptic number.

It is an amenable number.

644435141 is a deficient number, since it is larger than the sum of its proper divisors (137955259).

644435141 is a wasteful number, since it uses less digits than its factorization.

644435141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44588.

The product of its digits is 23040, while the sum is 32.

The square root of 644435141 is about 25385.7271119029. The cubic root of 644435141 is about 863.7599664177.

Adding to 644435141 its reverse (141534446), we get a palindrome (785969587).

The spelling of 644435141 in words is "six hundred forty-four million, four hundred thirty-five thousand, one hundred forty-one".