28177979 has 4 divisors (see below), whose sum is σ = 28939584. Its totient is φ = 27416376.

The previous prime is 28177949. The next prime is 28177991. The reversal of 28177979 is 97977182.

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 28177979 - 2¹² = 28173883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28177909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 380747 + ... + 380820.

It is an arithmetic number, because the mean of its divisors is an integer number (7234896).

Almost surely, 2^28177979 is an apocalyptic number.

28177979 is a deficient number, since it is larger than the sum of its proper divisors (761605).

28177979 is an equidigital number, since it uses as much as digits as its factorization.

28177979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 761604.

The product of its digits is 444528, while the sum is 50.

The square root of 28177979 is about 5308.2934169091. The cubic root of 28177979 is about 304.3009305127.

The spelling of 28177979 in words is "twenty-eight million, one hundred seventy-seven thousand, nine hundred seventy-nine".