28722155 has 32 divisors (see below), whose sum is σ = 43711488. Its totient is φ = 17596800.

The previous prime is 28722149. The next prime is 28722157. The reversal of 28722155 is 55122782.

It is a happy number.

It is not a de Polignac number, because 28722155 - 2⁸ = 28721899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28722157) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22874 + ... + 24096.

It is an arithmetic number, because the mean of its divisors is an integer number (1365984).

Almost surely, 2^28722155 is an apocalyptic number.

28722155 is a deficient number, since it is larger than the sum of its proper divisors (14989333).

28722155 is a wasteful number, since it uses less digits than its factorization.

28722155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1307.

The product of its digits is 11200, while the sum is 32.

The square root of 28722155 is about 5359.3054587325. The cubic root of 28722155 is about 306.2473508031.

The spelling of 28722155 in words is "twenty-eight million, seven hundred twenty-two thousand, one hundred fifty-five".