28156657 has 2 divisors, whose sum is σ = 28156658. Its totient is φ = 28156656.

The previous prime is 28156643. The next prime is 28156673. The reversal of 28156657 is 75665182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25969216 + 2187441 = 5096^2 + 1479^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28156657 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28156697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14078328 + 14078329.

It is an arithmetic number, because the mean of its divisors is an integer number (14078329).

Almost surely, 2^28156657 is an apocalyptic number.

It is an amenable number.

28156657 is a deficient number, since it is larger than the sum of its proper divisors (1).

28156657 is an equidigital number, since it uses as much as digits as its factorization.

28156657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 100800, while the sum is 40.

The square root of 28156657 is about 5306.2846700870. The cubic root of 28156657 is about 304.2241573030.

The spelling of 28156657 in words is "twenty-eight million, one hundred fifty-six thousand, six hundred fifty-seven".