21228301 has 4 divisors (see below), whose sum is σ = 22345600. Its totient is φ = 20111004.

The previous prime is 21228289. The next prime is 21228307. The reversal of 21228301 is 10382212.

21228301 = 1048² + 1049² + ... + 1066².

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 21228301 - 2¹³ = 21220109 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 1117279 = 21228301 / (2 + 1 + 2 + 2 + 8 + 3 + 0 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21228307) 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, 558621 + ... + 558658.

It is an arithmetic number, because the mean of its divisors is an integer number (5586400).

Almost surely, 2^21228301 is an apocalyptic number.

21228301 is the 2061-st centered decagonal number.

It is an amenable number.

21228301 is a deficient number, since it is larger than the sum of its proper divisors (1117299).

21228301 is a wasteful number, since it uses less digits than its factorization.

21228301 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1117298.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 21228301 is about 4607.4180405082. The cubic root of 21228301 is about 276.8886022630. Note that the first 3 decimals are identical.

The spelling of 21228301 in words is "twenty-one million, two hundred twenty-eight thousand, three hundred one".