21106026 has 24 divisors (see below), whose sum is σ = 47307780. Its totient is φ = 6792576.

The previous prime is 21105977. The next prime is 21106037. The reversal of 21106026 is 62060112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20385225 + 720801 = 4515^2 + 849^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19695 + ... + 20738.

Almost surely, 2^21106026 is an apocalyptic number.

21106026 is an abundant number, since it is smaller than the sum of its proper divisors (26201754).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21106026 is a wasteful number, since it uses less digits than its factorization.

21106026 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40470 (or 40467 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 21106026 is about 4594.1295149353. The cubic root of 21106026 is about 276.3559522057.

Adding to 21106026 its reverse (62060112), we get a palindrome (83166138).

The spelling of 21106026 in words is "twenty-one million, one hundred six thousand, twenty-six".