28402840 has 64 divisors (see below), whose sum is σ = 66173760. Its totient is φ = 10967040.

The previous prime is 28402819. The next prime is 28402879. The reversal of 28402840 is 4820482.

It is a junction number, because it is equal to n+sod(n) for n = 28402799 and 28402808.

It is a congruent number.

It is an unprimeable number.

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, 207252 + ... + 207388.

It is an arithmetic number, because the mean of its divisors is an integer number (1033965).

Almost surely, 2^28402840 is an apocalyptic number.

28402840 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 28402840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33086880).

28402840 is an abundant number, since it is smaller than the sum of its proper divisors (37770920).

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

28402840 is a wasteful number, since it uses less digits than its factorization.

28402840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292 (or 288 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 28.

The square root of 28402840 is about 5329.4314893805. The cubic root of 28402840 is about 305.1082299764.

The spelling of 28402840 in words is "twenty-eight million, four hundred two thousand, eight hundred forty".