21036131 has 2 divisors, whose sum is σ = 21036132. Its totient is φ = 21036130.

The previous prime is 21036083. The next prime is 21036133. The reversal of 21036131 is 13163012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21036131 - 2²² = 16841827 is a prime.

It is a super-2 number, since 2×21036131² = 885037614898322, which contains 22 as substring.

Together with 21036133, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21036133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10518065 + 10518066.

It is an arithmetic number, because the mean of its divisors is an integer number (10518066).

Almost surely, 2^21036131 is an apocalyptic number.

21036131 is a deficient number, since it is larger than the sum of its proper divisors (1).

21036131 is an equidigital number, since it uses as much as digits as its factorization.

21036131 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 21036131 is about 4586.5162160402. The cubic root of 21036131 is about 276.0505534717.

Adding to 21036131 its reverse (13163012), we get a palindrome (34199143).

The spelling of 21036131 in words is "twenty-one million, thirty-six thousand, one hundred thirty-one".