28722157 has 2 divisors, whose sum is σ = 28722158. Its totient is φ = 28722156.

The previous prime is 28722149. The next prime is 28722179. The reversal of 28722157 is 75122782.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22714756 + 6007401 = 4766^2 + 2451^2 .

It is a cyclic number.

It is not a de Polignac number, because 28722157 - 2³ = 28722149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28722107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14361078 + 14361079.

It is an arithmetic number, because the mean of its divisors is an integer number (14361079).

Almost surely, 2^28722157 is an apocalyptic number.

It is an amenable number.

28722157 is a deficient number, since it is larger than the sum of its proper divisors (1).

28722157 is an equidigital number, since it uses as much as digits as its factorization.

28722157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15680, while the sum is 34.

The square root of 28722157 is about 5359.3056453238. The cubic root of 28722157 is about 306.2473579114.

The spelling of 28722157 in words is "twenty-eight million, seven hundred twenty-two thousand, one hundred fifty-seven".