21117007 has 2 divisors, whose sum is σ = 21117008. Its totient is φ = 21117006.

The previous prime is 21117001. The next prime is 21117029. The reversal of 21117007 is 70071112.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21117007 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21117001) 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, 10558503 + 10558504.

It is an arithmetic number, because the mean of its divisors is an integer number (10558504).

Almost surely, 2^21117007 is an apocalyptic number.

21117007 is a deficient number, since it is larger than the sum of its proper divisors (1).

21117007 is an equidigital number, since it uses as much as digits as its factorization.

21117007 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 98, while the sum is 19.

The square root of 21117007 is about 4595.3244716777. The cubic root of 21117007 is about 276.4038711993.

Adding to 21117007 its reverse (70071112), we get a palindrome (91188119).

The spelling of 21117007 in words is "twenty-one million, one hundred seventeen thousand, seven".