28154021 has 4 divisors (see below), whose sum is σ = 32176032. Its totient is φ = 24132012.

The previous prime is 28154011. The next prime is 28154051. The reversal of 28154021 is 12045182.

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 28154021 - 2²² = 23959717 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28154011) 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, 2010995 + ... + 2011008.

It is an arithmetic number, because the mean of its divisors is an integer number (8044008).

Almost surely, 2^28154021 is an apocalyptic number.

It is an amenable number.

28154021 is a deficient number, since it is larger than the sum of its proper divisors (4022011).

28154021 is an equidigital number, since it uses as much as digits as its factorization.

28154021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4022010.

The product of its (nonzero) digits is 640, while the sum is 23.

The square root of 28154021 is about 5306.0362795593. The cubic root of 28154021 is about 304.2146632793.

The spelling of 28154021 in words is "twenty-eight million, one hundred fifty-four thousand, twenty-one".