89391821 has 2 divisors, whose sum is σ = 89391822. Its totient is φ = 89391820.

The previous prime is 89391787. The next prime is 89391829. The reversal of 89391821 is 12819398.

89391821 = 6685² + 6686².

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 44702596 + 44689225 = 6686^2 + 6685^2 .

It is a cyclic number.

It is not a de Polignac number, because 89391821 - 2²⁶ = 22282957 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (89391829) 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, 44695910 + 44695911.

It is an arithmetic number, because the mean of its divisors is an integer number (44695911).

Almost surely, 2^89391821 is an apocalyptic number.

89391821 is the 6686-th centered square number.

It is an amenable number.

89391821 is a deficient number, since it is larger than the sum of its proper divisors (1).

89391821 is an equidigital number, since it uses as much as digits as its factorization.

89391821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31104, while the sum is 41.

The square root of 89391821 is about 9454.7247976871. The cubic root of 89391821 is about 447.1287492371.

The spelling of 89391821 in words is "eighty-nine million, three hundred ninety-one thousand, eight hundred twenty-one".