28405042 has 4 divisors (see below), whose sum is σ = 42607566. Its totient is φ = 14202520.

The previous prime is 28405037. The next prime is 28405051. The reversal of 28405042 is 24050482.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 25310961 + 3094081 = 5031^2 + 1759^2 .

It is a super-2 number, since 2×28405042² = 1613692822043528, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28404998 and 28405016.

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 as a sum of consecutive naturals, namely, 7101259 + ... + 7101262.

Almost surely, 2^28405042 is an apocalyptic number.

28405042 is a deficient number, since it is larger than the sum of its proper divisors (14202524).

28405042 is a wasteful number, since it uses less digits than its factorization.

28405042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14202523.

The product of its (nonzero) digits is 2560, while the sum is 25.

The square root of 28405042 is about 5329.6380740159. The cubic root of 28405042 is about 305.1161145279.

The spelling of 28405042 in words is "twenty-eight million, four hundred five thousand, forty-two".