28156779 has 12 divisors (see below), whose sum is σ = 46481136. Its totient is φ = 16089552.

The previous prime is 28156769. The next prime is 28156781. The reversal of 28156779 is 97765182.

28156779 is a `hidden beast` number, since 2 + 81 + 567 + 7 + 9 = 666.

It is not a de Polignac number, because 28156779 - 2⁴ = 28156763 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28156769) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 223404 + ... + 223529.

It is an arithmetic number, because the mean of its divisors is an integer number (3873428).

Almost surely, 2^28156779 is an apocalyptic number.

28156779 is a deficient number, since it is larger than the sum of its proper divisors (18324357).

28156779 is a wasteful number, since it uses less digits than its factorization.

28156779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 446946 (or 446943 counting only the distinct ones).

The product of its digits is 211680, while the sum is 45.

The square root of 28156779 is about 5306.2961658769. The cubic root of 28156779 is about 304.2245966934.

The spelling of 28156779 in words is "twenty-eight million, one hundred fifty-six thousand, seven hundred seventy-nine".