28621889 has 2 divisors, whose sum is σ = 28621890. Its totient is φ = 28621888.

The previous prime is 28621877. The next prime is 28621891. The reversal of 28621889 is 98812682.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28143025 + 478864 = 5305^2 + 692^2 .

It is a cyclic number.

It is not a de Polignac number, because 28621889 - 2⁸ = 28621633 is a prime.

Together with 28621891, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28621819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14310944 + 14310945.

It is an arithmetic number, because the mean of its divisors is an integer number (14310945).

Almost surely, 2^28621889 is an apocalyptic number.

It is an amenable number.

28621889 is a deficient number, since it is larger than the sum of its proper divisors (1).

28621889 is an equidigital number, since it uses as much as digits as its factorization.

28621889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 110592, while the sum is 44.

The square root of 28621889 is about 5349.9428968915. The cubic root of 28621889 is about 305.8905763082.

The spelling of 28621889 in words is "twenty-eight million, six hundred twenty-one thousand, eight hundred eighty-nine".