21466221 has 8 divisors (see below), whose sum is σ = 32710464. Its totient is φ = 12266400.

The previous prime is 21466201. The next prime is 21466243. The reversal of 21466221 is 12266412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21466221 - 2⁶ = 21466157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21466191 and 21466200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21466201) 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 7 ways as a sum of consecutive naturals, for example, 511080 + ... + 511121.

It is an arithmetic number, because the mean of its divisors is an integer number (4088808).

Almost surely, 2^21466221 is an apocalyptic number.

21466221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21466221 is a deficient number, since it is larger than the sum of its proper divisors (11244243).

21466221 is a wasteful number, since it uses less digits than its factorization.

21466221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1022211.

The product of its digits is 1152, while the sum is 24.

The square root of 21466221 is about 4633.1653326856. The cubic root of 21466221 is about 277.9191879044.

It can be divided in two parts, 21 and 466221, that multiplied together give a square (9790641 = 3129²).

The spelling of 21466221 in words is "twenty-one million, four hundred sixty-six thousand, two hundred twenty-one".