8631719221 has 2 divisors, whose sum is σ = 8631719222. Its totient is φ = 8631719220.

The previous prime is 8631719141. The next prime is 8631719227. The reversal of 8631719221 is 1229171368.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7989856996 + 641862225 = 89386^2 + 25335^2 .

It is a cyclic number.

It is not a de Polignac number, because 8631719221 - 2¹³ = 8631711029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8631719227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4315859610 + 4315859611.

It is an arithmetic number, because the mean of its divisors is an integer number (4315859611).

Almost surely, 2^8631719221 is an apocalyptic number.

It is an amenable number.

8631719221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8631719221 is an equidigital number, since it uses as much as digits as its factorization.

8631719221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36288, while the sum is 40.

The square root of 8631719221 is about 92907.0461321422. The cubic root of 8631719221 is about 2051.3153740186.

The spelling of 8631719221 in words is "eight billion, six hundred thirty-one million, seven hundred nineteen thousand, two hundred twenty-one".