21226706 has 4 divisors (see below), whose sum is σ = 31840062. Its totient is φ = 10613352.

The previous prime is 21226703. The next prime is 21226729. The reversal of 21226706 is 60762212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20784481 + 442225 = 4559^2 + 665^2 .

It is a super-2 number, since 2×21226706² = 901146095220872, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21226703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5306675 + ... + 5306678.

Almost surely, 2^21226706 is an apocalyptic number.

21226706 is a deficient number, since it is larger than the sum of its proper divisors (10613356).

21226706 is a wasteful number, since it uses less digits than its factorization.

21226706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10613355.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 21226706 is about 4607.2449468202. The cubic root of 21226706 is about 276.8816673639.

Adding to 21226706 its reverse (60762212), we get a palindrome (81988918).

The spelling of 21226706 in words is "twenty-one million, two hundred twenty-six thousand, seven hundred six".