28274420 has 54 divisors (see below), whose sum is σ = 63030786. Its totient is φ = 10653440.

The previous prime is 28274381. The next prime is 28274431. The reversal of 28274420 is 2447282.

It can be written as a sum of positive squares in 9 ways, for example, as 20106256 + 8168164 = 4484^2 + 2858^2 .

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a congruent number.

It is an unprimeable number.

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 17 ways as a sum of consecutive naturals, for example, 689600 + ... + 689640.

Almost surely, 2^28274420 is an apocalyptic number.

28274420 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 28274420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31515393).

28274420 is an abundant number, since it is smaller than the sum of its proper divisors (34756366).

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

28274420 is a wasteful number, since it uses less digits than its factorization.

28274420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149 (or 77 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 29.

The square root of 28274420 is about 5317.3696504945. The cubic root of 28274420 is about 304.6476985660.

The spelling of 28274420 in words is "twenty-eight million, two hundred seventy-four thousand, four hundred twenty".