28757971 has 4 divisors (see below), whose sum is σ = 31372344. Its totient is φ = 26143600.

The previous prime is 28757969. The next prime is 28757977. The reversal of 28757971 is 17975782.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28757971 - 2¹ = 28757969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28757977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1307170 + ... + 1307191.

It is an arithmetic number, because the mean of its divisors is an integer number (7843086).

Almost surely, 2^28757971 is an apocalyptic number.

28757971 is a deficient number, since it is larger than the sum of its proper divisors (2614373).

28757971 is a wasteful number, since it uses less digits than its factorization.

28757971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2614372.

The product of its digits is 246960, while the sum is 46.

The square root of 28757971 is about 5362.6458954512. The cubic root of 28757971 is about 306.3745928697.

The spelling of 28757971 in words is "twenty-eight million, seven hundred fifty-seven thousand, nine hundred seventy-one".