889996721 has 2 divisors, whose sum is σ = 889996722. Its totient is φ = 889996720.

The previous prime is 889996703. The next prime is 889996739. The reversal of 889996721 is 127699988.

It is a balanced prime because it is at equal distance from previous prime (889996703) and next prime (889996739).

It can be written as a sum of positive squares in only one way, i.e., 613107121 + 276889600 = 24761^2 + 16640^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-889996721 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (889996781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 444998360 + 444998361.

It is an arithmetic number, because the mean of its divisors is an integer number (444998361).

Almost surely, 2^889996721 is an apocalyptic number.

It is an amenable number.

889996721 is a deficient number, since it is larger than the sum of its proper divisors (1).

889996721 is an equidigital number, since it uses as much as digits as its factorization.

889996721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3919104, while the sum is 59.

The square root of 889996721 is about 29832.8128241371. The cubic root of 889996721 is about 961.8989903064.

It can be divided in two parts, 8899967 and 21, that added together give a palindrome (8899988).

The spelling of 889996721 in words is "eight hundred eighty-nine million, nine hundred ninety-six thousand, seven hundred twenty-one".