21129626 has 16 divisors (see below), whose sum is σ = 36576384. Its totient is φ = 8967024.

The previous prime is 21129613. The next prime is 21129643. The reversal of 21129626 is 62692112.

It is a happy number.

It is a super-2 number, since 2×21129626² = 892922189799752, 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, 5885 + ... + 8768.

It is an arithmetic number, because the mean of its divisors is an integer number (2286024).

Almost surely, 2^21129626 is an apocalyptic number.

21129626 is a deficient number, since it is larger than the sum of its proper divisors (15446758).

21129626 is a wasteful number, since it uses less digits than its factorization.

21129626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14765.

The product of its digits is 2592, while the sum is 29.

The square root of 21129626 is about 4596.6972926222. The cubic root of 21129626 is about 276.4589176036.

The spelling of 21129626 in words is "twenty-one million, one hundred twenty-nine thousand, six hundred twenty-six".