21036937 has 2 divisors, whose sum is σ = 21036938. Its totient is φ = 21036936.

The previous prime is 21036929. The next prime is 21036947. The reversal of 21036937 is 73963012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20967241 + 69696 = 4579^2 + 264^2 .

It is a cyclic number.

It is not a de Polignac number, because 21036937 - 2³ = 21036929 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21036899 and 21036908.

It is not a weakly prime, because it can be changed into another prime (21036947) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10518468 + 10518469.

It is an arithmetic number, because the mean of its divisors is an integer number (10518469).

Almost surely, 2^21036937 is an apocalyptic number.

It is an amenable number.

21036937 is a deficient number, since it is larger than the sum of its proper divisors (1).

21036937 is an equidigital number, since it uses as much as digits as its factorization.

21036937 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6804, while the sum is 31.

The square root of 21036937 is about 4586.6040814529. The cubic root of 21036937 is about 276.0540790552.

Adding to 21036937 its reverse (73963012), we get a palindrome (94999949).

The spelling of 21036937 in words is "twenty-one million, thirty-six thousand, nine hundred thirty-seven".