21127499 has 2 divisors, whose sum is σ = 21127500. Its totient is φ = 21127498.

The previous prime is 21127493. The next prime is 21127507. The reversal of 21127499 is 99472112.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21127499 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21127493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10563749 + 10563750.

It is an arithmetic number, because the mean of its divisors is an integer number (10563750).

Almost surely, 2^21127499 is an apocalyptic number.

21127499 is a deficient number, since it is larger than the sum of its proper divisors (1).

21127499 is an equidigital number, since it uses as much as digits as its factorization.

21127499 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9072, while the sum is 35.

The square root of 21127499 is about 4596.4659250341. The cubic root of 21127499 is about 276.4496407735.

The spelling of 21127499 in words is "twenty-one million, one hundred twenty-seven thousand, four hundred ninety-nine".