644436141 has 16 divisors (see below), whose sum is σ = 903000384. Its totient is φ = 408288384.

The previous prime is 644436137. The next prime is 644436161. The reversal of 644436141 is 141634446.

It is not a de Polignac number, because 644436141 - 2² = 644436137 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644436131) 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, 62736 + ... + 72281.

It is an arithmetic number, because the mean of its divisors is an integer number (56437524).

Almost surely, 2^644436141 is an apocalyptic number.

It is an amenable number.

644436141 is a deficient number, since it is larger than the sum of its proper divisors (258564243).

644436141 is a wasteful number, since it uses less digits than its factorization.

644436141 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135100.

The product of its digits is 27648, while the sum is 33.

The square root of 644436141 is about 25385.7468080023. The cubic root of 644436141 is about 863.7604131963.

The spelling of 644436141 in words is "six hundred forty-four million, four hundred thirty-six thousand, one hundred forty-one".