21161137 has 2 divisors, whose sum is σ = 21161138. Its totient is φ = 21161136.

The previous prime is 21161131. The next prime is 21161191. The reversal of 21161137 is 73116112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15610401 + 5550736 = 3951^2 + 2356^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21161137 is a prime.

It is not a weakly prime, because it can be changed into another prime (21161131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10580568 + 10580569.

It is an arithmetic number, because the mean of its divisors is an integer number (10580569).

Almost surely, 2^21161137 is an apocalyptic number.

It is an amenable number.

21161137 is a deficient number, since it is larger than the sum of its proper divisors (1).

21161137 is an equidigital number, since it uses as much as digits as its factorization.

21161137 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 252, while the sum is 22.

The square root of 21161137 is about 4600.1235852964. The cubic root of 21161137 is about 276.5962787665.

Adding to 21161137 its reverse (73116112), we get a palindrome (94277249).

The spelling of 21161137 in words is "twenty-one million, one hundred sixty-one thousand, one hundred thirty-seven".