21125393 has 2 divisors, whose sum is σ = 21125394. Its totient is φ = 21125392.

The previous prime is 21125389. The next prime is 21125443. The reversal of 21125393 is 39352112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13601344 + 7524049 = 3688^2 + 2743^2 .

It is a cyclic number.

It is not a de Polignac number, because 21125393 - 2² = 21125389 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21125303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562696 + 10562697.

It is an arithmetic number, because the mean of its divisors is an integer number (10562697).

Almost surely, 2^21125393 is an apocalyptic number.

It is an amenable number.

21125393 is a deficient number, since it is larger than the sum of its proper divisors (1).

21125393 is an equidigital number, since it uses as much as digits as its factorization.

21125393 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1620, while the sum is 26.

The square root of 21125393 is about 4596.2368302776. The cubic root of 21125393 is about 276.4404549207.

The spelling of 21125393 in words is "twenty-one million, one hundred twenty-five thousand, three hundred ninety-three".