21251226 has 8 divisors (see below), whose sum is σ = 42502464. Its totient is φ = 7083740.

The previous prime is 21251201. The next prime is 21251239. The reversal of 21251226 is 62215212.

It is a happy number.

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

21251226 is an admirable number.

It is a super-2 number, since 2×21251226² = 903229213006152, which contains 22 as substring.

It is a plaindrome in base 16.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1770930 + ... + 1770941.

It is an arithmetic number, because the mean of its divisors is an integer number (5312808).

Almost surely, 2^21251226 is an apocalyptic number.

21251226 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21251226 is a wasteful number, since it uses less digits than its factorization.

21251226 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3541876.

The product of its digits is 480, while the sum is 21.

The square root of 21251226 is about 4609.9052050991. The cubic root of 21251226 is about 276.9882394969.

Adding to 21251226 its reverse (62215212), we get a palindrome (83466438).

The spelling of 21251226 in words is "twenty-one million, two hundred fifty-one thousand, two hundred twenty-six".