28782971 has 4 divisors (see below), whose sum is σ = 32894832. Its totient is φ = 24671112.

The previous prime is 28782961. The next prime is 28782979. The reversal of 28782971 is 17928782.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17928782 = 2 ⋅8964391.

It is a cyclic number.

It is not a de Polignac number, because 28782971 - 2¹⁴ = 28766587 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28782979) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2055920 + ... + 2055933.

It is an arithmetic number, because the mean of its divisors is an integer number (8223708).

Almost surely, 2^28782971 is an apocalyptic number.

28782971 is a deficient number, since it is larger than the sum of its proper divisors (4111861).

28782971 is an equidigital number, since it uses as much as digits as its factorization.

28782971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4111860.

The product of its digits is 112896, while the sum is 44.

The square root of 28782971 is about 5364.9763280000. The cubic root of 28782971 is about 306.4633467715.

The spelling of 28782971 in words is "twenty-eight million, seven hundred eighty-two thousand, nine hundred seventy-one".