872518781 has 2 divisors, whose sum is σ = 872518782. Its totient is φ = 872518780.

The previous prime is 872518747. The next prime is 872518789. The reversal of 872518781 is 187815278.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 754600900 + 117917881 = 27470^2 + 10859^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-872518781 is a prime.

It is a super-2 number, since 2×872518781² = 1522578046395451922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (872518789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 436259390 + 436259391.

It is an arithmetic number, because the mean of its divisors is an integer number (436259391).

Almost surely, 2^872518781 is an apocalyptic number.

It is an amenable number.

872518781 is a deficient number, since it is larger than the sum of its proper divisors (1).

872518781 is an equidigital number, since it uses as much as digits as its factorization.

872518781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 250880, while the sum is 47.

The square root of 872518781 is about 29538.4288850981. The cubic root of 872518781 is about 955.5606590622.

The spelling of 872518781 in words is "eight hundred seventy-two million, five hundred eighteen thousand, seven hundred eighty-one".