869179981 has 2 divisors, whose sum is σ = 869179982. Its totient is φ = 869179980.

The previous prime is 869179979. The next prime is 869180069. The reversal of 869179981 is 189971968.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 791915881 + 77264100 = 28141^2 + 8790^2 .

It is a cyclic number.

It is not a de Polignac number, because 869179981 - 2¹ = 869179979 is a prime.

It is a super-2 number, since 2×869179981² = 1510947678742320722, which contains 22 as substring.

Together with 869179979, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (869179921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 434589990 + 434589991.

It is an arithmetic number, because the mean of its divisors is an integer number (434589991).

Almost surely, 2^869179981 is an apocalyptic number.

It is an amenable number.

869179981 is a deficient number, since it is larger than the sum of its proper divisors (1).

869179981 is an equidigital number, since it uses as much as digits as its factorization.

869179981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1959552, while the sum is 58.

The square root of 869179981 is about 29481.8585065460. The cubic root of 869179981 is about 954.3402444075.

The spelling of 869179981 in words is "eight hundred sixty-nine million, one hundred seventy-nine thousand, nine hundred eighty-one".