21732037 has 2 divisors, whose sum is σ = 21732038. Its totient is φ = 21732036.

The previous prime is 21732017. The next prime is 21732041. The reversal of 21732037 is 73023712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19088161 + 2643876 = 4369^2 + 1626^2 .

It is a cyclic number.

It is not a de Polignac number, because 21732037 - 2¹⁵ = 21699269 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21732017) 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, 10866018 + 10866019.

It is an arithmetic number, because the mean of its divisors is an integer number (10866019).

Almost surely, 2^21732037 is an apocalyptic number.

It is an amenable number.

21732037 is a deficient number, since it is larger than the sum of its proper divisors (1).

21732037 is an equidigital number, since it uses as much as digits as its factorization.

21732037 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1764, while the sum is 25.

The square root of 21732037 is about 4661.7632930041. The cubic root of 21732037 is about 279.0616419770.

Adding to 21732037 its reverse (73023712), we get a palindrome (94755749).

The spelling of 21732037 in words is "twenty-one million, seven hundred thirty-two thousand, thirty-seven".