28123490 has 16 divisors (see below), whose sum is σ = 50847480. Its totient is φ = 11199360.

The previous prime is 28123489. The next prime is 28123493. The reversal of 28123490 is 9432182.

It can be written as a sum of positive squares in 4 ways, for example, as 28121809 + 1681 = 5303^2 + 41^2 .

It is not an unprimeable number, because it can be changed into a prime (28123493) 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 7 ways as a sum of consecutive naturals, for example, 3851 + ... + 8430.

Almost surely, 2^28123490 is an apocalyptic number.

28123490 is a deficient number, since it is larger than the sum of its proper divisors (22723990).

28123490 is a wasteful number, since it uses less digits than its factorization.

28123490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12517.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 28123490 is about 5303.1584928229. The cubic root of 28123490 is about 304.1046572368.

The spelling of 28123490 in words is "twenty-eight million, one hundred twenty-three thousand, four hundred ninety".