28349440 has 132 divisors (see below), whose sum is σ = 79808436. Its totient is φ = 9633792.

The previous prime is 28349429. The next prime is 28349471. The reversal of 28349440 is 4494382.

It can be written as a sum of positive squares in 2 ways, for example, as 4064256 + 24285184 = 2016^2 + 4928^2 .

It is a junction number, because it is equal to n+sod(n) for n = 28349396 and 28349405.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 250824 + ... + 250936.

Almost surely, 2^28349440 is an apocalyptic number.

28349440 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 28349440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39904218).

28349440 is an abundant number, since it is smaller than the sum of its proper divisors (51458996).

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

28349440 is a wasteful number, since it uses less digits than its factorization.

28349440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152 (or 127 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 34.

The square root of 28349440 is about 5324.4192171541. The cubic root of 28349440 is about 304.9168993347.

The spelling of 28349440 in words is "twenty-eight million, three hundred forty-nine thousand, four hundred forty".