21231135 has 12 divisors (see below), whose sum is σ = 36800712. Its totient is φ = 11323248.

The previous prime is 21231107. The next prime is 21231143. The reversal of 21231135 is 53113212.

It is not a de Polignac number, because 21231135 - 2⁸ = 21230879 is a prime.

It is a super-2 number, since 2×21231135² = 901522186776450, which contains 22 as substring.

It is a congruent number.

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, 235857 + ... + 235946.

It is an arithmetic number, because the mean of its divisors is an integer number (3066726).

Almost surely, 2^21231135 is an apocalyptic number.

21231135 is a deficient number, since it is larger than the sum of its proper divisors (15569577).

21231135 is a wasteful number, since it uses less digits than its factorization.

21231135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 471814 (or 471811 counting only the distinct ones).

The product of its digits is 180, while the sum is 18.

The square root of 21231135 is about 4607.7255777661. The cubic root of 21231135 is about 276.9009233524.

Adding to 21231135 its reverse (53113212), we get a palindrome (74344347).

The spelling of 21231135 in words is "twenty-one million, two hundred thirty-one thousand, one hundred thirty-five".