28077780 has 24 divisors (see below), whose sum is σ = 78617952. Its totient is φ = 7487392.

The previous prime is 28077773. The next prime is 28077781. The reversal of 28077780 is 8777082.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28077781) 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, 233922 + ... + 234041.

It is an arithmetic number, because the mean of its divisors is an integer number (3275748).

Almost surely, 2^28077780 is an apocalyptic number.

28077780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28077780 is an abundant number, since it is smaller than the sum of its proper divisors (50540172).

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

28077780 is a wasteful number, since it uses less digits than its factorization.

28077780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 467975 (or 467973 counting only the distinct ones).

The product of its (nonzero) digits is 43904, while the sum is 39.

The square root of 28077780 is about 5298.8470444050. The cubic root of 28077780 is about 303.9398109140.

The spelling of 28077780 in words is "twenty-eight million, seventy-seven thousand, seven hundred eighty".