21127493 has 2 divisors, whose sum is σ = 21127494. Its totient is φ = 21127492.

The previous prime is 21127459. The next prime is 21127499. The reversal of 21127493 is 39472112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16662724 + 4464769 = 4082^2 + 2113^2 .

It is a cyclic number.

It is not a de Polignac number, because 21127493 - 2²⁴ = 4350277 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 (21127499) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10563746 + 10563747.

It is an arithmetic number, because the mean of its divisors is an integer number (10563747).

Almost surely, 2^21127493 is an apocalyptic number.

It is an amenable number.

21127493 is a deficient number, since it is larger than the sum of its proper divisors (1).

21127493 is an equidigital number, since it uses as much as digits as its factorization.

21127493 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 29.

The square root of 21127493 is about 4596.4652723588. The cubic root of 21127493 is about 276.4496146038.

The spelling of 21127493 in words is "twenty-one million, one hundred twenty-seven thousand, four hundred ninety-three".