21226137 has 16 divisors (see below), whose sum is σ = 28998528. Its totient is φ = 13806720.

The previous prime is 21226111. The next prime is 21226141. The reversal of 21226137 is 73162212.

It is not a de Polignac number, because 21226137 - 2⁸ = 21225881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21226147) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22087 + ... + 23027.

It is an arithmetic number, because the mean of its divisors is an integer number (1812408).

Almost surely, 2^21226137 is an apocalyptic number.

It is an amenable number.

21226137 is a deficient number, since it is larger than the sum of its proper divisors (7772391).

21226137 is a wasteful number, since it uses less digits than its factorization.

21226137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1120.

The product of its digits is 1008, while the sum is 24.

The square root of 21226137 is about 4607.1831958367. The cubic root of 21226137 is about 276.8791933252.

Adding to 21226137 its reverse (73162212), we get a palindrome (94388349).

The spelling of 21226137 in words is "twenty-one million, two hundred twenty-six thousand, one hundred thirty-seven".