21303137 has 2 divisors, whose sum is σ = 21303138. Its totient is φ = 21303136.

The previous prime is 21303131. The next prime is 21303143. The reversal of 21303137 is 73130312.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (21303131) and next prime (21303143).

It can be written as a sum of positive squares in only one way, i.e., 12327121 + 8976016 = 3511^2 + 2996^2 .

It is a cyclic number.

It is not a de Polignac number, because 21303137 - 2⁸ = 21302881 is a prime.

It is not a weakly prime, because it can be changed into another prime (21303131) 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, 10651568 + 10651569.

It is an arithmetic number, because the mean of its divisors is an integer number (10651569).

Almost surely, 2^21303137 is an apocalyptic number.

It is an amenable number.

21303137 is a deficient number, since it is larger than the sum of its proper divisors (1).

21303137 is an equidigital number, since it uses as much as digits as its factorization.

21303137 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 378, while the sum is 20.

The square root of 21303137 is about 4615.5321470010. The cubic root of 21303137 is about 277.2135919005.

Adding to 21303137 its reverse (73130312), we get a palindrome (94433449).

The spelling of 21303137 in words is "twenty-one million, three hundred three thousand, one hundred thirty-seven".