28777878 has 24 divisors (see below), whose sum is σ = 62457408. Its totient is φ = 9576432.

The previous prime is 28777877. The next prime is 28777901. The reversal of 28777878 is 87877782.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28777877) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14875 + ... + 16697.

It is an arithmetic number, because the mean of its divisors is an integer number (2602392).

Almost surely, 2^28777878 is an apocalyptic number.

28777878 is an abundant number, since it is smaller than the sum of its proper divisors (33679530).

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

28777878 is a wasteful number, since it uses less digits than its factorization.

28777878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2708 (or 2705 counting only the distinct ones).

The product of its digits is 2458624, while the sum is 54.

The square root of 28777878 is about 5364.5016543944. The cubic root of 28777878 is about 306.4452699963.

The spelling of 28777878 in words is "twenty-eight million, seven hundred seventy-seven thousand, eight hundred seventy-eight".