28771889 has 2 divisors, whose sum is σ = 28771890. Its totient is φ = 28771888.

The previous prime is 28771819. The next prime is 28771901. The reversal of 28771889 is 98817782.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19651489 + 9120400 = 4433^2 + 3020^2 .

It is a cyclic number.

It is not a de Polignac number, because 28771889 - 2²⁰ = 27723313 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28771819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14385944 + 14385945.

It is an arithmetic number, because the mean of its divisors is an integer number (14385945).

Almost surely, 2^28771889 is an apocalyptic number.

It is an amenable number.

28771889 is a deficient number, since it is larger than the sum of its proper divisors (1).

28771889 is an equidigital number, since it uses as much as digits as its factorization.

28771889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 451584, while the sum is 50.

The square root of 28771889 is about 5363.9434187918. The cubic root of 28771889 is about 306.4240102859.

The spelling of 28771889 in words is "twenty-eight million, seven hundred seventy-one thousand, eight hundred eighty-nine".