21150037 has 2 divisors, whose sum is σ = 21150038. Its totient is φ = 21150036.

The previous prime is 21150011. The next prime is 21150043. The reversal of 21150037 is 73005112.

It is the 1878-th star number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19000881 + 2149156 = 4359^2 + 1466^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21150037 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21149996 and 21150023.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21150067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10575018 + 10575019.

It is an arithmetic number, because the mean of its divisors is an integer number (10575019).

Almost surely, 2^21150037 is an apocalyptic number.

It is an amenable number.

21150037 is a deficient number, since it is larger than the sum of its proper divisors (1).

21150037 is an equidigital number, since it uses as much as digits as its factorization.

21150037 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 210, while the sum is 19.

The square root of 21150037 is about 4598.9169377148. The cubic root of 21150037 is about 276.5479077728.

Adding to 21150037 its reverse (73005112), we get a palindrome (94155149).

The spelling of 21150037 in words is "twenty-one million, one hundred fifty thousand, thirty-seven".