28777988 has 6 divisors (see below), whose sum is σ = 50361486. Its totient is φ = 14388992.

The previous prime is 28777981. The next prime is 28777997. The reversal of 28777988 is 88977782.

It can be written as a sum of positive squares in only one way, i.e., 25421764 + 3356224 = 5042^2 + 1832^2 .

It is not an unprimeable number, because it can be changed into a prime (28777981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3597245 + ... + 3597252.

It is an arithmetic number, because the mean of its divisors is an integer number (8393581).

Almost surely, 2^28777988 is an apocalyptic number.

It is an amenable number.

28777988 is a deficient number, since it is larger than the sum of its proper divisors (21583498).

28777988 is a wasteful number, since it uses less digits than its factorization.

28777988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7194501 (or 7194499 counting only the distinct ones).

The product of its digits is 3161088, while the sum is 56.

The square root of 28777988 is about 5364.5119069679. The cubic root of 28777988 is about 306.4456604459.

The spelling of 28777988 in words is "twenty-eight million, seven hundred seventy-seven thousand, nine hundred eighty-eight".