28779420 has 48 divisors (see below), whose sum is σ = 81567360. Its totient is φ = 7580736.

The previous prime is 28779391. The next prime is 28779431. The reversal of 28779420 is 2497782.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2091 + ... + 7869.

It is an arithmetic number, because the mean of its divisors is an integer number (1699320).

Almost surely, 2^28779420 is an apocalyptic number.

28779420 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 28779420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40783680).

28779420 is an abundant number, since it is smaller than the sum of its proper divisors (52787940).

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

28779420 is a wasteful number, since it uses less digits than its factorization.

28779420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5874 (or 5872 counting only the distinct ones).

The product of its (nonzero) digits is 56448, while the sum is 39.

The square root of 28779420 is about 5364.6453750458. The cubic root of 28779420 is about 306.4507432996.

The spelling of 28779420 in words is "twenty-eight million, seven hundred seventy-nine thousand, four hundred twenty".