21351135 has 32 divisors (see below), whose sum is σ = 37029888. Its totient is φ = 10442880.

The previous prime is 21351131. The next prime is 21351181. The reversal of 21351135 is 53115312.

It is not a de Polignac number, because 21351135 - 2² = 21351131 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21351131) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 43240 + ... + 43730.

It is an arithmetic number, because the mean of its divisors is an integer number (1157184).

Almost surely, 2^21351135 is an apocalyptic number.

21351135 is a deficient number, since it is larger than the sum of its proper divisors (15678753).

21351135 is a wasteful number, since it uses less digits than its factorization.

21351135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 735.

The product of its digits is 450, while the sum is 21.

The square root of 21351135 is about 4620.7288386141. The cubic root of 21351135 is about 277.4216319569.

Adding to 21351135 its reverse (53115312), we get a palindrome (74466447).

The spelling of 21351135 in words is "twenty-one million, three hundred fifty-one thousand, one hundred thirty-five".