21037361 has 2 divisors, whose sum is σ = 21037362. Its totient is φ = 21037360.

The previous prime is 21037339. The next prime is 21037369. The reversal of 21037361 is 16373012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19749136 + 1288225 = 4444^2 + 1135^2 .

It is a cyclic number.

It is not a de Polignac number, because 21037361 - 2¹⁸ = 20775217 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21037369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10518680 + 10518681.

It is an arithmetic number, because the mean of its divisors is an integer number (10518681).

Almost surely, 2^21037361 is an apocalyptic number.

It is an amenable number.

21037361 is a deficient number, since it is larger than the sum of its proper divisors (1).

21037361 is an equidigital number, since it uses as much as digits as its factorization.

21037361 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 756, while the sum is 23.

The square root of 21037361 is about 4586.6503027809. The cubic root of 21037361 is about 276.0559336684.

The spelling of 21037361 in words is "twenty-one million, thirty-seven thousand, three hundred sixty-one".