28427989 has 2 divisors, whose sum is σ = 28427990. Its totient is φ = 28427988.

The previous prime is 28427969. The next prime is 28428007. The reversal of 28427989 is 98972482.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19624900 + 8803089 = 4430^2 + 2967^2 .

It is a cyclic number.

It is not a de Polignac number, because 28427989 - 2⁵ = 28427957 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 (28427929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14213994 + 14213995.

It is an arithmetic number, because the mean of its divisors is an integer number (14213995).

Almost surely, 2^28427989 is an apocalyptic number.

It is an amenable number.

28427989 is a deficient number, since it is larger than the sum of its proper divisors (1).

28427989 is an equidigital number, since it uses as much as digits as its factorization.

28427989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 580608, while the sum is 49.

The square root of 28427989 is about 5331.7904122349. The cubic root of 28427989 is about 305.1982550500.

The spelling of 28427989 in words is "twenty-eight million, four hundred twenty-seven thousand, nine hundred eighty-nine".