869143981 has 2 divisors, whose sum is σ = 869143982. Its totient is φ = 869143980.

The previous prime is 869143903. The next prime is 869144021. The reversal of 869143981 is 189341968.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 525968356 + 343175625 = 22934^2 + 18525^2 .

It is a cyclic number.

It is not a de Polignac number, because 869143981 - 2⁹ = 869143469 is a prime.

It is a super-2 number, since 2×869143981² = 1510822519417056722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (869143901) 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, 434571990 + 434571991.

It is an arithmetic number, because the mean of its divisors is an integer number (434571991).

Almost surely, 2^869143981 is an apocalyptic number.

It is an amenable number.

869143981 is a deficient number, since it is larger than the sum of its proper divisors (1).

869143981 is an equidigital number, since it uses as much as digits as its factorization.

869143981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 373248, while the sum is 49.

The square root of 869143981 is about 29481.2479552681. The cubic root of 869143981 is about 954.3270684931.

The spelling of 869143981 in words is "eight hundred sixty-nine million, one hundred forty-three thousand, nine hundred eighty-one".