21126626 has 4 divisors (see below), whose sum is σ = 31689942. Its totient is φ = 10563312.

The previous prime is 21126617. The next prime is 21126629. The reversal of 21126626 is 62662112.

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., 17648401 + 3478225 = 4201^2 + 1865^2 .

It is a super-2 number, since 2×21126626² = 892668652287752, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21126595 and 21126604.

It is not an unprimeable number, because it can be changed into a prime (21126629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5281655 + ... + 5281658.

Almost surely, 2^21126626 is an apocalyptic number.

21126626 is a deficient number, since it is larger than the sum of its proper divisors (10563316).

21126626 is a wasteful number, since it uses less digits than its factorization.

21126626 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10563315.

The product of its digits is 1728, while the sum is 26.

The square root of 21126626 is about 4596.3709597899. The cubic root of 21126626 is about 276.4458330368.

Adding to 21126626 its reverse (62662112), we get a palindrome (83788738).

The spelling of 21126626 in words is "twenty-one million, one hundred twenty-six thousand, six hundred twenty-six".