28121430 has 32 divisors (see below), whose sum is σ = 68167008. Its totient is φ = 7424000.

The previous prime is 28121413. The next prime is 28121453. The reversal of 28121430 is 3412182.

It is a junction number, because it is equal to n+sod(n) for n = 28121397 and 28121406.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1611 + ... + 7670.

It is an arithmetic number, because the mean of its divisors is an integer number (2130219).

Almost surely, 2^28121430 is an apocalyptic number.

28121430 is an abundant number, since it is smaller than the sum of its proper divisors (40045578).

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

28121430 is a wasteful number, since it uses less digits than its factorization.

28121430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9392.

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 28121430 is about 5302.9642653897. The cubic root of 28121430 is about 304.0972319980.

The spelling of 28121430 in words is "twenty-eight million, one hundred twenty-one thousand, four hundred thirty".