82641991 has 2 divisors, whose sum is σ = 82641992. Its totient is φ = 82641990.

The previous prime is 82641983. The next prime is 82641997. The reversal of 82641991 is 19914628.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 82641991 - 2³ = 82641983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (82641997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41320995 + 41320996.

It is an arithmetic number, because the mean of its divisors is an integer number (41320996).

Almost surely, 2^82641991 is an apocalyptic number.

82641991 is a deficient number, since it is larger than the sum of its proper divisors (1).

82641991 is an equidigital number, since it uses as much as digits as its factorization.

82641991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 40.

The square root of 82641991 is about 9090.7640492975. The cubic root of 82641991 is about 435.5789903220.

The spelling of 82641991 in words is "eighty-two million, six hundred forty-one thousand, nine hundred ninety-one".