72871809617 has 2 divisors, whose sum is σ = 72871809618. Its totient is φ = 72871809616.

The previous prime is 72871809613. The next prime is 72871809631. The reversal of 72871809617 is 71690817827.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64801302721 + 8070506896 = 254561^2 + 89836^2 .

It is a cyclic number.

It is not a de Polignac number, because 72871809617 - 2² = 72871809613 is a prime.

It is not a weakly prime, because it can be changed into another prime (72871809613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36435904808 + 36435904809.

It is an arithmetic number, because the mean of its divisors is an integer number (36435904809).

Almost surely, 2^72871809617 is an apocalyptic number.

It is an amenable number.

72871809617 is a deficient number, since it is larger than the sum of its proper divisors (1).

72871809617 is an equidigital number, since it uses as much as digits as its factorization.

72871809617 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2370816, while the sum is 56.

The spelling of 72871809617 in words is "seventy-two billion, eight hundred seventy-one million, eight hundred nine thousand, six hundred seventeen".