28704971 has 4 divisors (see below), whose sum is σ = 28863744. Its totient is φ = 28546200.

The previous prime is 28704947. The next prime is 28704979. The reversal of 28704971 is 17940782.

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 28704971 - 2¹⁰ = 28703947 is a prime.

It is a super-2 number, since 2×28704971² = 1647950720221682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28704979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79115 + ... + 79476.

It is an arithmetic number, because the mean of its divisors is an integer number (7215936).

Almost surely, 2^28704971 is an apocalyptic number.

28704971 is a deficient number, since it is larger than the sum of its proper divisors (158773).

28704971 is a wasteful number, since it uses less digits than its factorization.

28704971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158772.

The product of its (nonzero) digits is 28224, while the sum is 38.

The square root of 28704971 is about 5357.7020260556. The cubic root of 28704971 is about 306.1862643430.

The spelling of 28704971 in words is "twenty-eight million, seven hundred four thousand, nine hundred seventy-one".