28240019 has 4 divisors (see below), whose sum is σ = 28254744. Its totient is φ = 28225296.

The previous prime is 28240013. The next prime is 28240027. The reversal of 28240019 is 91004282.

28240019 is nontrivially palindromic in base 14.

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

It is a cyclic number.

It is not a de Polignac number, because 28240019 - 2¹² = 28235923 is a prime.

It is a super-2 number, since 2×28240019² = 1594997346240722, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28240019.

It is not an unprimeable number, because it can be changed into a prime (28240013) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3962 + ... + 8495.

It is an arithmetic number, because the mean of its divisors is an integer number (7063686).

Almost surely, 2^28240019 is an apocalyptic number.

28240019 is a deficient number, since it is larger than the sum of its proper divisors (14725).

28240019 is a wasteful number, since it uses less digits than its factorization.

28240019 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14724.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 28240019 is about 5314.1338899204. The cubic root of 28240019 is about 304.5240952206.

The spelling of 28240019 in words is "twenty-eight million, two hundred forty thousand, nineteen".