21226690 has 16 divisors (see below), whose sum is σ = 38485440. Its totient is φ = 8429040.

The previous prime is 21226687. The next prime is 21226703. The reversal of 21226690 is 9662212.

It is a super-2 number, since 2×21226690² = 901144736712200, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6246 + ... + 9025.

It is an arithmetic number, because the mean of its divisors is an integer number (2405340).

Almost surely, 2^21226690 is an apocalyptic number.

21226690 is a deficient number, since it is larger than the sum of its proper divisors (17258750).

21226690 is a wasteful number, since it uses less digits than its factorization.

21226690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15417.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 21226690 is about 4607.2432104242. The cubic root of 21226690 is about 276.8815977957.

The spelling of 21226690 in words is "twenty-one million, two hundred twenty-six thousand, six hundred ninety".