28873621 has 4 divisors (see below), whose sum is σ = 32998432. Its totient is φ = 24748812.

The previous prime is 28873613. The next prime is 28873627. The reversal of 28873621 is 12637882.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28873621 - 2³ = 28873613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28873627) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 2062395 + ... + 2062408.

It is an arithmetic number, because the mean of its divisors is an integer number (8249608).

Almost surely, 2^28873621 is an apocalyptic number.

It is an amenable number.

28873621 is a deficient number, since it is larger than the sum of its proper divisors (4124811).

28873621 is an equidigital number, since it uses as much as digits as its factorization.

28873621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4124810.

The product of its digits is 32256, while the sum is 37.

The square root of 28873621 is about 5373.4179997465. The cubic root of 28873621 is about 306.7847380625.

The spelling of 28873621 in words is "twenty-eight million, eight hundred seventy-three thousand, six hundred twenty-one".