28981879 has 2 divisors, whose sum is σ = 28981880. Its totient is φ = 28981878.

The previous prime is 28981877. The next prime is 28981891. The reversal of 28981879 is 97818982.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28981879 - 2¹ = 28981877 is a prime.

Together with 28981877, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28981873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14490939 + 14490940.

It is an arithmetic number, because the mean of its divisors is an integer number (14490940).

Almost surely, 2^28981879 is an apocalyptic number.

28981879 is a deficient number, since it is larger than the sum of its proper divisors (1).

28981879 is an equidigital number, since it uses as much as digits as its factorization.

28981879 is an evil number, because the sum of its binary digits is even.

The product of its digits is 580608, while the sum is 52.

The square root of 28981879 is about 5383.4820516093. The cubic root of 28981879 is about 307.1676767602.

The spelling of 28981879 in words is "twenty-eight million, nine hundred eighty-one thousand, eight hundred seventy-nine".