644540301 has 8 divisors (see below), whose sum is σ = 954874560. Its totient is φ = 429693516.

The previous prime is 644540269. The next prime is 644540311. The reversal of 644540301 is 103045446.

It is not a de Polignac number, because 644540301 - 2⁵ = 644540269 is a prime.

It is a super-2 number, since 2×644540301² = 830864399226341202, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 23871863 = 644540301 / (6 + 4 + 4 + 5 + 4 + 0 + 3 + 0 + 1).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644540311) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11935905 + ... + 11935958.

It is an arithmetic number, because the mean of its divisors is an integer number (119359320).

Almost surely, 2^644540301 is an apocalyptic number.

It is an amenable number.

644540301 is a deficient number, since it is larger than the sum of its proper divisors (310334259).

644540301 is a wasteful number, since it uses less digits than its factorization.

644540301 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23871872 (or 23871866 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

The square root of 644540301 is about 25387.7982700352. The cubic root of 644540301 is about 863.8069471258.

Adding to 644540301 its reverse (103045446), we get a palindrome (747585747).

The spelling of 644540301 in words is "six hundred forty-four million, five hundred forty thousand, three hundred one".