28776978 has 16 divisors (see below), whose sum is σ = 63948960. Its totient is φ = 9592308.

The previous prime is 28776977. The next prime is 28776997. The reversal of 28776978 is 87967782.

It is a super-2 number, since 2×28776978² = 1656228925624968, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54), and also a Moran number because the ratio is a prime number: 532907 = 28776978 / (2 + 8 + 7 + 7 + 6 + 9 + 7 + 8).

It is not an unprimeable number, because it can be changed into a prime (28776973) 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, 266400 + ... + 266507.

It is an arithmetic number, because the mean of its divisors is an integer number (3996810).

Almost surely, 2^28776978 is an apocalyptic number.

28776978 is an abundant number, since it is smaller than the sum of its proper divisors (35171982).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28776978 is a wasteful number, since it uses less digits than its factorization.

28776978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 532918 (or 532912 counting only the distinct ones).

The product of its digits is 2370816, while the sum is 54.

The square root of 28776978 is about 5364.4177689662. The cubic root of 28776978 is about 306.4420753709.

The spelling of 28776978 in words is "twenty-eight million, seven hundred seventy-six thousand, nine hundred seventy-eight".