28709978 has 16 divisors (see below), whose sum is σ = 47075904. Its totient is φ = 13023360.

The previous prime is 28709977. The next prime is 28709981. The reversal of 28709978 is 87990782.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (28709977) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13226 + ... + 15242.

It is an arithmetic number, because the mean of its divisors is an integer number (2942244).

Almost surely, 2^28709978 is an apocalyptic number.

28709978 is a deficient number, since it is larger than the sum of its proper divisors (18365926).

28709978 is a wasteful number, since it uses less digits than its factorization.

28709978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2677.

The product of its (nonzero) digits is 508032, while the sum is 50.

The square root of 28709978 is about 5358.1692769079. The cubic root of 28709978 is about 306.2040659693.

The spelling of 28709978 in words is "twenty-eight million, seven hundred nine thousand, nine hundred seventy-eight".