28091404 has 24 divisors (see below), whose sum is σ = 53964288. Its totient is φ = 12689040.

The previous prime is 28091369. The next prime is 28091423. The reversal of 28091404 is 40419082.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5437 + ... + 9259.

It is an arithmetic number, because the mean of its divisors is an integer number (2248512).

Almost surely, 2^28091404 is an apocalyptic number.

It is an amenable number.

28091404 is a deficient number, since it is larger than the sum of its proper divisors (25872884).

28091404 is a wasteful number, since it uses less digits than its factorization.

28091404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4005 (or 4003 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 28091404 is about 5300.1324511752. The cubic root of 28091404 is about 303.9889625494.

It can be divided in two parts, 2809 and 1404, that multiplied together give a triangular number (3943836 = T₂₈₀₈).

The spelling of 28091404 in words is "twenty-eight million, ninety-one thousand, four hundred four".