21013226 has 36 divisors (see below), whose sum is σ = 36325926. Its totient is φ = 9061920.

The previous prime is 21013217. The next prime is 21013249. The reversal of 21013226 is 62231012.

It can be written as a sum of positive squares in 3 ways, for example, as 15015625 + 5997601 = 3875^2 + 2449^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 677831 + ... + 677861.

Almost surely, 2^21013226 is an apocalyptic number.

21013226 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

21013226 is a deficient number, since it is larger than the sum of its proper divisors (15312700).

21013226 is a wasteful number, since it uses less digits than its factorization.

21013226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135 (or 75 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21013226 is about 4584.0185427199. The cubic root of 21013226 is about 275.9503253736.

Adding to 21013226 its reverse (62231012), we get a palindrome (83244238).

The spelling of 21013226 in words is "twenty-one million, thirteen thousand, two hundred twenty-six".