889439342821 has 2 divisors, whose sum is σ = 889439342822. Its totient is φ = 889439342820.

The previous prime is 889439342819. The next prime is 889439342837. The reversal of 889439342821 is 128243934988.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 839614853025 + 49824489796 = 916305^2 + 223214^2 .

It is a cyclic number.

It is not a de Polignac number, because 889439342821 - 2¹ = 889439342819 is a prime.

It is a super-2 number, since 2×889439342821² (a number of 25 digits) contains 22 as substring.

Together with 889439342819, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 889439342821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (889439342021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 444719671410 + 444719671411.

It is an arithmetic number, because the mean of its divisors is an integer number (444719671411).

Almost surely, 2^889439342821 is an apocalyptic number.

It is an amenable number.

889439342821 is a deficient number, since it is larger than the sum of its proper divisors (1).

889439342821 is an equidigital number, since it uses as much as digits as its factorization.

889439342821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23887872, while the sum is 61.

The spelling of 889439342821 in words is "eight hundred eighty-nine billion, four hundred thirty-nine million, three hundred forty-two thousand, eight hundred twenty-one".