21266446 has 4 divisors (see below), whose sum is σ = 31899672. Its totient is φ = 10633222.

The previous prime is 21266411. The next prime is 21266449. The reversal of 21266446 is 64466212.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21266449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5316610 + ... + 5316613.

It is an arithmetic number, because the mean of its divisors is an integer number (7974918).

Almost surely, 2^21266446 is an apocalyptic number.

21266446 is a deficient number, since it is larger than the sum of its proper divisors (10633226).

21266446 is a wasteful number, since it uses less digits than its factorization.

21266446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10633225.

The product of its digits is 13824, while the sum is 31.

The square root of 21266446 is about 4611.5557027971. Note that the first 3 decimals coincide. The cubic root of 21266446 is about 277.0543494862.

It can be divided in two parts, 21266 and 446, that added together give a palindrome (21712).

The spelling of 21266446 in words is "twenty-one million, two hundred sixty-six thousand, four hundred forty-six".