21223135 has 16 divisors (see below), whose sum is σ = 26749440. Its totient is φ = 16133920.

The previous prime is 21223093. The next prime is 21223141. The reversal of 21223135 is 53132212.

It is not a de Polignac number, because 21223135 - 2¹⁷ = 21092063 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20070 + ... + 21100.

It is an arithmetic number, because the mean of its divisors is an integer number (1671840).

Almost surely, 2^21223135 is an apocalyptic number.

21223135 is a deficient number, since it is larger than the sum of its proper divisors (5526305).

21223135 is a wasteful number, since it uses less digits than its factorization.

21223135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1238.

The product of its digits is 360, while the sum is 19.

The square root of 21223135 is about 4606.8573887196. The cubic root of 21223135 is about 276.8661397562.

Adding to 21223135 its reverse (53132212), we get a palindrome (74355347).

The spelling of 21223135 in words is "twenty-one million, two hundred twenty-three thousand, one hundred thirty-five".