21037117 has 2 divisors, whose sum is σ = 21037118. Its totient is φ = 21037116.

The previous prime is 21037103. The next prime is 21037139. The reversal of 21037117 is 71173012.

It is an a-pointer prime, because the next prime (21037139) can be obtained adding 21037117 to its sum of digits (22).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16818201 + 4218916 = 4101^2 + 2054^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21037117 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21037187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10518558 + 10518559.

It is an arithmetic number, because the mean of its divisors is an integer number (10518559).

Almost surely, 2^21037117 is an apocalyptic number.

It is an amenable number.

21037117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21037117 is an equidigital number, since it uses as much as digits as its factorization.

21037117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 294, while the sum is 22.

The square root of 21037117 is about 4586.6237037717. The cubic root of 21037117 is about 276.0548663940.

The spelling of 21037117 in words is "twenty-one million, thirty-seven thousand, one hundred seventeen".