28766978 has 4 divisors (see below), whose sum is σ = 43150470. Its totient is φ = 14383488.

The previous prime is 28766971. The next prime is 28766989. The reversal of 28766978 is 87966782.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87966782 = 2 ⋅43983391.

It can be written as a sum of positive squares in only one way, i.e., 14876449 + 13890529 = 3857^2 + 3727^2 .

It is not an unprimeable number, because it can be changed into a prime (28766971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7191743 + ... + 7191746.

Almost surely, 2^28766978 is an apocalyptic number.

28766978 is a deficient number, since it is larger than the sum of its proper divisors (14383492).

28766978 is a wasteful number, since it uses less digits than its factorization.

28766978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14383491.

The product of its digits is 2032128, while the sum is 53.

The square root of 28766978 is about 5363.4856203779. The cubic root of 28766978 is about 306.4065750509.

The spelling of 28766978 in words is "twenty-eight million, seven hundred sixty-six thousand, nine hundred seventy-eight".