21740027 has 2 divisors, whose sum is σ = 21740028. Its totient is φ = 21740026.

The previous prime is 21740023. The next prime is 21740029. The reversal of 21740027 is 72004712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21740027 - 2² = 21740023 is a prime.

Together with 21740029, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 21739984 and 21740011.

It is not a weakly prime, because it can be changed into another prime (21740023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10870013 + 10870014.

It is an arithmetic number, because the mean of its divisors is an integer number (10870014).

Almost surely, 2^21740027 is an apocalyptic number.

21740027 is a deficient number, since it is larger than the sum of its proper divisors (1).

21740027 is an equidigital number, since it uses as much as digits as its factorization.

21740027 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 784, while the sum is 23.

The square root of 21740027 is about 4662.6201861185. The cubic root of 21740027 is about 279.0958377178.

Adding to 21740027 its reverse (72004712), we get a palindrome (93744739).

The spelling of 21740027 in words is "twenty-one million, seven hundred forty thousand, twenty-seven".