644765122085 has 8 divisors (see below), whose sum is σ = 884249310336. Its totient is φ = 442124655120.

The previous prime is 644765122039. The next prime is 644765122103. The reversal of 644765122085 is 580221567446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 644765122085 - 2²⁰ = 644764073509 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9210930281 + ... + 9210930350.

It is an arithmetic number, because the mean of its divisors is an integer number (110531163792).

Almost surely, 2^644765122085 is an apocalyptic number.

It is an amenable number.

644765122085 is a deficient number, since it is larger than the sum of its proper divisors (239484188251).

644765122085 is a wasteful number, since it uses less digits than its factorization.

644765122085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18421860643.

The product of its (nonzero) digits is 3225600, while the sum is 50.

The spelling of 644765122085 in words is "six hundred forty-four billion, seven hundred sixty-five million, one hundred twenty-two thousand, eighty-five".