7844621217245 has 16 divisors (see below), whose sum is σ = 9809231891760. Its totient is φ = 6015065193984.

The previous prime is 7844621217241. The next prime is 7844621217247. The reversal of 7844621217245 is 5427121264487.

It can be written as a sum of positive squares in 8 ways, for example, as 5455595044 + 7839165622201 = 73862^2 + 2799851^2 .

It is a cyclic number.

It is not a de Polignac number, because 7844621217245 - 2² = 7844621217241 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7844621217241) 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, 197428442 + ... + 197468171.

It is an arithmetic number, because the mean of its divisors is an integer number (613076993235).

Almost surely, 2^{7844621217245} is an apocalyptic number.

It is an amenable number.

7844621217245 is a deficient number, since it is larger than the sum of its proper divisors (1964610674515).

7844621217245 is a wasteful number, since it uses less digits than its factorization.

7844621217245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 394896784.

The product of its digits is 6021120, while the sum is 53.

The spelling of 7844621217245 in words is "seven trillion, eight hundred forty-four billion, six hundred twenty-one million, two hundred seventeen thousand, two hundred forty-five".