8464821991 has 2 divisors, whose sum is σ = 8464821992. Its totient is φ = 8464821990.

The previous prime is 8464821983. The next prime is 8464822013. The reversal of 8464821991 is 1991284648.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 8464821991 - 2³ = 8464821983 is a prime.

It is a super-2 number, since 2×8464821991² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8464822991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4232410995 + 4232410996.

It is an arithmetic number, because the mean of its divisors is an integer number (4232410996).

Almost surely, 2^8464821991 is an apocalyptic number.

8464821991 is a deficient number, since it is larger than the sum of its proper divisors (1).

8464821991 is an equidigital number, since it uses as much as digits as its factorization.

8464821991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 995328, while the sum is 52.

The square root of 8464821991 is about 92004.4672339338. The cubic root of 8464821991 is about 2038.0082757491.

The spelling of 8464821991 in words is "eight billion, four hundred sixty-four million, eight hundred twenty-one thousand, nine hundred ninety-one".