28777980 has 96 divisors (see below), whose sum is σ = 100477440. Its totient is φ = 5978880.

The previous prime is 28777979. The next prime is 28777981. The reversal of 28777980 is 8977782.

It is an interprime number because it is at equal distance from previous prime (28777979) and next prime (28777981).

It is a congruent number.

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

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1506 + ... + 7734.

It is an arithmetic number, because the mean of its divisors is an integer number (1046640).

Almost surely, 2^28777980 is an apocalyptic number.

28777980 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28777980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50238720).

28777980 is an abundant number, since it is smaller than the sum of its proper divisors (71699460).

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

28777980 is a wasteful number, since it uses less digits than its factorization.

28777980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6259 (or 6257 counting only the distinct ones).

The product of its (nonzero) digits is 395136, while the sum is 48.

The square root of 28777980 is about 5364.5111613268. The cubic root of 28777980 is about 306.4456320496.

The spelling of 28777980 in words is "twenty-eight million, seven hundred seventy-seven thousand, nine hundred eighty".