21517127 has 2 divisors, whose sum is σ = 21517128. Its totient is φ = 21517126.

The previous prime is 21517109. The next prime is 21517163. The reversal of 21517127 is 72171512.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21517127 - 2⁸ = 21516871 is a prime.

It is a Chen prime.

It is equal to p_1360592 and since 21517127 and 1360592 have the same sum of digits, it is a Honaker prime.

It is a junction number, because it is equal to n+sod(n) for n = 21517096 and 21517105.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21517187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10758563 + 10758564.

It is an arithmetic number, because the mean of its divisors is an integer number (10758564).

Almost surely, 2^21517127 is an apocalyptic number.

21517127 is a deficient number, since it is larger than the sum of its proper divisors (1).

21517127 is an equidigital number, since it uses as much as digits as its factorization.

21517127 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 980, while the sum is 26.

The square root of 21517127 is about 4638.6557319982. The cubic root of 21517127 is about 278.1387046565.

Adding to 21517127 its reverse (72171512), we get a palindrome (93688639).

The spelling of 21517127 in words is "twenty-one million, five hundred seventeen thousand, one hundred twenty-seven".