28157971 has 2 divisors, whose sum is σ = 28157972. Its totient is φ = 28157970.

The previous prime is 28157959. The next prime is 28157977. The reversal of 28157971 is 17975182.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28157971 - 2¹⁵ = 28125203 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (28157977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14078985 + 14078986.

It is an arithmetic number, because the mean of its divisors is an integer number (14078986).

Almost surely, 2^28157971 is an apocalyptic number.

28157971 is a deficient number, since it is larger than the sum of its proper divisors (1).

28157971 is an equidigital number, since it uses as much as digits as its factorization.

28157971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35280, while the sum is 40.

The square root of 28157971 is about 5306.4084840879. The cubic root of 28157971 is about 304.2288896868.

The spelling of 28157971 in words is "twenty-eight million, one hundred fifty-seven thousand, nine hundred seventy-one".