28122979 has 4 divisors (see below), whose sum is σ = 28224784. Its totient is φ = 28021176.

The previous prime is 28122977. The next prime is 28123057. The reversal of 28122979 is 97922182.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28122979 - 2¹ = 28122977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28122971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50487 + ... + 51040.

It is an arithmetic number, because the mean of its divisors is an integer number (7056196).

Almost surely, 2^28122979 is an apocalyptic number.

28122979 is a deficient number, since it is larger than the sum of its proper divisors (101805).

28122979 is a wasteful number, since it uses less digits than its factorization.

28122979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101804.

The product of its digits is 36288, while the sum is 40.

The square root of 28122979 is about 5303.1103137687. The cubic root of 28122979 is about 304.1028153789.

The spelling of 28122979 in words is "twenty-eight million, one hundred twenty-two thousand, nine hundred seventy-nine".