28402220 has 48 divisors (see below), whose sum is σ = 74366208. Its totient is φ = 8852160.

The previous prime is 28402219. The next prime is 28402229. The reversal of 28402220 is 2220482.

It is a super-2 number, since 2×28402220² = 1613372201856800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 28402192 and 28402201.

It is not an unprimeable number, because it can be changed into a prime (28402229) 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, 7682 + ... + 10761.

It is an arithmetic number, because the mean of its divisors is an integer number (1549296).

Almost surely, 2^28402220 is an apocalyptic number.

28402220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28402220 is an abundant number, since it is smaller than the sum of its proper divisors (45963988).

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

28402220 is a wasteful number, since it uses less digits than its factorization.

28402220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18470 (or 18468 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 28402220 is about 5329.3733215079. The cubic root of 28402220 is about 305.1060099111.

The spelling of 28402220 in words is "twenty-eight million, four hundred two thousand, two hundred twenty".