21037193 has 4 divisors (see below), whose sum is σ = 21146388. Its totient is φ = 20928000.

The previous prime is 21037187. The next prime is 21037207. The reversal of 21037193 is 39173012.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6801664 + 14235529 = 2608^2 + 3773^2 .

It is a cyclic number.

It is not a de Polignac number, because 21037193 - 2⁸ = 21036937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21037103) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54308 + ... + 54693.

It is an arithmetic number, because the mean of its divisors is an integer number (5286597).

Almost surely, 2^21037193 is an apocalyptic number.

It is an amenable number.

21037193 is a deficient number, since it is larger than the sum of its proper divisors (109195).

21037193 is a wasteful number, since it uses less digits than its factorization.

21037193 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109194.

The product of its (nonzero) digits is 1134, while the sum is 26.

The square root of 21037193 is about 4586.6319887255. The cubic root of 21037193 is about 276.0551988246.

The spelling of 21037193 in words is "twenty-one million, thirty-seven thousand, one hundred ninety-three".