917072154821 has 2 divisors, whose sum is σ = 917072154822. Its totient is φ = 917072154820.

The previous prime is 917072154797. The next prime is 917072154919. The reversal of 917072154821 is 128451270719.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 901956681796 + 15115473025 = 949714^2 + 122945^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-917072154821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (917072154121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 458536077410 + 458536077411.

It is an arithmetic number, because the mean of its divisors is an integer number (458536077411).

Almost surely, 2^917072154821 is an apocalyptic number.

It is an amenable number.

917072154821 is a deficient number, since it is larger than the sum of its proper divisors (1).

917072154821 is an equidigital number, since it uses as much as digits as its factorization.

917072154821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 282240, while the sum is 47.

The spelling of 917072154821 in words is "nine hundred seventeen billion, seventy-two million, one hundred fifty-four thousand, eight hundred twenty-one".