28420420 has 48 divisors (see below), whose sum is σ = 69810048. Its totient is φ = 9515520.

The previous prime is 28420411. The next prime is 28420429. The reversal of 28420420 is 2402482.

It is an interprime number because it is at equal distance from previous prime (28420411) and next prime (28420429).

It is a junction number, because it is equal to n+sod(n) for n = 28420391 and 28420400.

It is not an unprimeable number, because it can be changed into a prime (28420429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3660 + ... + 8380.

It is an arithmetic number, because the mean of its divisors is an integer number (1454376).

Almost surely, 2^28420420 is an apocalyptic number.

28420420 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 28420420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34905024).

28420420 is an abundant number, since it is smaller than the sum of its proper divisors (41389628).

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

28420420 is a wasteful number, since it uses less digits than its factorization.

28420420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4780 (or 4778 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 22.

The square root of 28420420 is about 5331.0805658891. The cubic root of 28420420 is about 305.1711661290.

The spelling of 28420420 in words is "twenty-eight million, four hundred twenty thousand, four hundred twenty".