82591921 has 2 divisors, whose sum is σ = 82591922. Its totient is φ = 82591920.

The previous prime is 82591871. The next prime is 82591931. The reversal of 82591921 is 12919528.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 79210000 + 3381921 = 8900^2 + 1839^2 .

It is a cyclic number.

It is not a de Polignac number, because 82591921 - 2⁷ = 82591793 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (82591931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 41295960 + 41295961.

It is an arithmetic number, because the mean of its divisors is an integer number (41295961).

Almost surely, 2^82591921 is an apocalyptic number.

It is an amenable number.

82591921 is a deficient number, since it is larger than the sum of its proper divisors (1).

82591921 is an equidigital number, since it uses as much as digits as its factorization.

82591921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12960, while the sum is 37.

The square root of 82591921 is about 9088.0097381110. The cubic root of 82591921 is about 435.4910050020.

The spelling of 82591921 in words is "eighty-two million, five hundred ninety-one thousand, nine hundred twenty-one".