863773721 has 2 divisors, whose sum is σ = 863773722. Its totient is φ = 863773720.

The previous prime is 863773693. The next prime is 863773733. The reversal of 863773721 is 127377368.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 854743696 + 9030025 = 29236^2 + 3005^2 .

It is a cyclic number.

It is not a de Polignac number, because 863773721 - 2²⁶ = 796664857 is a prime.

It is a super-3 number, since 3×863773721³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (863773751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 431886860 + 431886861.

It is an arithmetic number, because the mean of its divisors is an integer number (431886861).

Almost surely, 2^863773721 is an apocalyptic number.

It is an amenable number.

863773721 is a deficient number, since it is larger than the sum of its proper divisors (1).

863773721 is an equidigital number, since it uses as much as digits as its factorization.

863773721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 296352, while the sum is 44.

The square root of 863773721 is about 29390.0275773943. The cubic root of 863773721 is about 952.3574768095.

The spelling of 863773721 in words is "eight hundred sixty-three million, seven hundred seventy-three thousand, seven hundred twenty-one".