21127313 has 2 divisors, whose sum is σ = 21127314. Its totient is φ = 21127312.

The previous prime is 21127307. The next prime is 21127321. The reversal of 21127313 is 31372112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20539024 + 588289 = 4532^2 + 767^2 .

It is a cyclic number.

It is not a de Polignac number, because 21127313 - 2¹⁰ = 21126289 is a prime.

It is not a weakly prime, because it can be changed into another prime (21127303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10563656 + 10563657.

It is an arithmetic number, because the mean of its divisors is an integer number (10563657).

Almost surely, 2^21127313 is an apocalyptic number.

It is an amenable number.

21127313 is a deficient number, since it is larger than the sum of its proper divisors (1).

21127313 is an equidigital number, since it uses as much as digits as its factorization.

21127313 is an evil number, because the sum of its binary digits is even.

The product of its digits is 252, while the sum is 20.

The square root of 21127313 is about 4596.4456920538. The cubic root of 21127313 is about 276.4488295119.

Adding to 21127313 its reverse (31372112), we get a palindrome (52499425).

It can be divided in two parts, 2 and 1127313, that multiplied together give a triangular number (2254626 = T₂₁₂₃).

The spelling of 21127313 in words is "twenty-one million, one hundred twenty-seven thousand, three hundred thirteen".