21406226 has 4 divisors (see below), whose sum is σ = 32109342. Its totient is φ = 10703112.

The previous prime is 21406207. The next prime is 21406237. The reversal of 21406226 is 62260412.

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., 12967201 + 8439025 = 3601^2 + 2905^2 .

It is a super-3 number, since 3×21406226³ (a number of 23 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5351555 + ... + 5351558.

Almost surely, 2^21406226 is an apocalyptic number.

21406226 is a deficient number, since it is larger than the sum of its proper divisors (10703116).

21406226 is a wasteful number, since it uses less digits than its factorization.

21406226 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10703115.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 21406226 is about 4626.6862871822. The cubic root of 21406226 is about 277.6600316013.

Adding to 21406226 its reverse (62260412), we get a palindrome (83666638).

The spelling of 21406226 in words is "twenty-one million, four hundred six thousand, two hundred twenty-six".