644540644030245 has 64 divisors (see below), whose sum is σ = 1076537047910400. Its totient is φ = 328914758430720.

The previous prime is 644540644030223. The next prime is 644540644030271. The reversal of 644540644030245 is 542030446045446.

It is not a de Polignac number, because 644540644030245 - 2⁴² = 640142597519141 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1044787041 + ... + 1045403769.

It is an arithmetic number, because the mean of its divisors is an integer number (16820891373600).

Almost surely, 2^{644540644030245} is an apocalyptic number.

It is an amenable number.

644540644030245 is a deficient number, since it is larger than the sum of its proper divisors (431996403880155).

644540644030245 is a wasteful number, since it uses less digits than its factorization.

644540644030245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 642110.

The product of its (nonzero) digits is 22118400, while the sum is 51.

The spelling of 644540644030245 in words is "six hundred forty-four trillion, five hundred forty billion, six hundred forty-four million, thirty thousand, two hundred forty-five".