21226161 has 8 divisors (see below), whose sum is σ = 30874464. Its totient is φ = 12864320.

The previous prime is 21226157. The next prime is 21226181. The reversal of 21226161 is 16162212.

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

It is a cyclic number.

It is not a de Polignac number, because 21226161 - 2² = 21226157 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21226111) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 321576 + ... + 321641.

It is an arithmetic number, because the mean of its divisors is an integer number (3859308).

Almost surely, 2^21226161 is an apocalyptic number.

It is an amenable number.

21226161 is a deficient number, since it is larger than the sum of its proper divisors (9648303).

21226161 is a wasteful number, since it uses less digits than its factorization.

21226161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643231.

The product of its digits is 288, while the sum is 21.

The square root of 21226161 is about 4607.1858004643. The cubic root of 21226161 is about 276.8792976792.

Adding to 21226161 its reverse (16162212), we get a palindrome (37388373).

The spelling of 21226161 in words is "twenty-one million, two hundred twenty-six thousand, one hundred sixty-one".