21131135 has 24 divisors (see below), whose sum is σ = 27980640. Its totient is φ = 15288768.

The previous prime is 21131087. The next prime is 21131137. The reversal of 21131135 is 53113112.

It is not a de Polignac number, because 21131135 - 2¹⁰ = 21130111 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21131137) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 41261 + ... + 41769.

It is an arithmetic number, because the mean of its divisors is an integer number (1165860).

Almost surely, 2^21131135 is an apocalyptic number.

21131135 is a deficient number, since it is larger than the sum of its proper divisors (6849505).

21131135 is a wasteful number, since it uses less digits than its factorization.

21131135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 575 (or 556 counting only the distinct ones).

The product of its digits is 90, while the sum is 17.

The square root of 21131135 is about 4596.8614292798. The cubic root of 21131135 is about 276.4654986725.

Adding to 21131135 its reverse (53113112), we get a palindrome (74244247).

The spelling of 21131135 in words is "twenty-one million, one hundred thirty-one thousand, one hundred thirty-five".