863989381 has 2 divisors, whose sum is σ = 863989382. Its totient is φ = 863989380.

The previous prime is 863989367. The next prime is 863989393. The reversal of 863989381 is 183989368.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 797158756 + 66830625 = 28234^2 + 8175^2 .

It is a cyclic number.

It is not a de Polignac number, because 863989381 - 2⁵ = 863989349 is a prime.

It is a super-2 number, since 2×863989381² = 1492955300961526322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (863989681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 431994690 + 431994691.

It is an arithmetic number, because the mean of its divisors is an integer number (431994691).

Almost surely, 2^863989381 is an apocalyptic number.

It is an amenable number.

863989381 is a deficient number, since it is larger than the sum of its proper divisors (1).

863989381 is an equidigital number, since it uses as much as digits as its factorization.

863989381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2239488, while the sum is 55.

The square root of 863989381 is about 29393.6962799849. The cubic root of 863989381 is about 952.4367291715.

The spelling of 863989381 in words is "eight hundred sixty-three million, nine hundred eighty-nine thousand, three hundred eighty-one".