28209073 has 4 divisors (see below), whose sum is σ = 28355428. Its totient is φ = 28062720.

The previous prime is 28209061. The next prime is 28209119. The reversal of 28209073 is 37090282.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13897984 + 14311089 = 3728^2 + 3783^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28209073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28209043) 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, 72888 + ... + 73273.

It is an arithmetic number, because the mean of its divisors is an integer number (7088857).

Almost surely, 2^28209073 is an apocalyptic number.

It is an amenable number.

28209073 is a deficient number, since it is larger than the sum of its proper divisors (146355).

28209073 is a wasteful number, since it uses less digits than its factorization.

28209073 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146354.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 28209073 is about 5311.2214226108. The cubic root of 28209073 is about 304.4128199530.

The spelling of 28209073 in words is "twenty-eight million, two hundred nine thousand, seventy-three".