21236131 has 8 divisors (see below), whose sum is σ = 24562944. Its totient is φ = 17982600.

The previous prime is 21236123. The next prime is 21236141. The reversal of 21236131 is 13163212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21236131 - 2³ = 21236123 is a prime.

It is a super-2 number, since 2×21236131² = 901946519698322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21236099 and 21236108.

It is not an unprimeable number, because it can be changed into a prime (21236101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17695 + ... + 18856.

It is an arithmetic number, because the mean of its divisors is an integer number (3070368).

Almost surely, 2^21236131 is an apocalyptic number.

21236131 is a deficient number, since it is larger than the sum of its proper divisors (3326813).

21236131 is an equidigital number, since it uses as much as digits as its factorization.

21236131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36641.

The product of its digits is 216, while the sum is 19.

The square root of 21236131 is about 4608.2676788572. The cubic root of 21236131 is about 276.9226412762.

Adding to 21236131 its reverse (13163212), we get a palindrome (34399343).

The spelling of 21236131 in words is "twenty-one million, two hundred thirty-six thousand, one hundred thirty-one".