1644545125237 has 12 divisors (see below), whose sum is σ = 1915349986380. Its totient is φ = 1407909698496.

The previous prime is 1644545125217. The next prime is 1644545125247. The reversal of 1644545125237 is 7325215454461.

It can be written as a sum of positive squares in 2 ways, for example, as 752670764356 + 891874360881 = 867566^2 + 944391^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1644545125237 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644545125217) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 20201928 + ... + 20283169.

It is an arithmetic number, because the mean of its divisors is an integer number (159612498865).

Almost surely, 2^{1644545125237} is an apocalyptic number.

It is an amenable number.

1644545125237 is a deficient number, since it is larger than the sum of its proper divisors (270804861143).

1644545125237 is an equidigital number, since it uses as much as digits as its factorization.

1644545125237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40485940 (or 40485933 counting only the distinct ones).

The product of its digits is 4032000, while the sum is 49.

The spelling of 1644545125237 in words is "one trillion, six hundred forty-four billion, five hundred forty-five million, one hundred twenty-five thousand, two hundred thirty-seven".