863447861 has 2 divisors, whose sum is σ = 863447862. Its totient is φ = 863447860.

The previous prime is 863447821. The next prime is 863447903. The reversal of 863447861 is 168744368.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 640393636 + 223054225 = 25306^2 + 14935^2 .

It is a cyclic number.

It is not a de Polignac number, because 863447861 - 2⁶ = 863447797 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (863447821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 431723930 + 431723931.

It is an arithmetic number, because the mean of its divisors is an integer number (431723931).

Almost surely, 2^863447861 is an apocalyptic number.

It is an amenable number.

863447861 is a deficient number, since it is larger than the sum of its proper divisors (1).

863447861 is an equidigital number, since it uses as much as digits as its factorization.

863447861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 774144, while the sum is 47.

The square root of 863447861 is about 29384.4833372990. The cubic root of 863447861 is about 952.2377022926.

The spelling of 863447861 in words is "eight hundred sixty-three million, four hundred forty-seven thousand, eight hundred sixty-one".