21161226 has 16 divisors (see below), whose sum is σ = 44812224. Its totient is φ = 6638784.

The previous prime is 21161191. The next prime is 21161227. The reversal of 21161226 is 62216112.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21161227) 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, 103630 + ... + 103833.

It is an arithmetic number, because the mean of its divisors is an integer number (2800764).

Almost surely, 2^21161226 is an apocalyptic number.

21161226 is an abundant number, since it is smaller than the sum of its proper divisors (23650998).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21161226 is a wasteful number, since it uses less digits than its factorization.

21161226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207485.

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

The square root of 21161226 is about 4600.1332589394. The cubic root of 21161226 is about 276.5966665376.

Adding to 21161226 its reverse (62216112), we get a palindrome (83377338).

The spelling of 21161226 in words is "twenty-one million, one hundred sixty-one thousand, two hundred twenty-six".