21118007 has 2 divisors, whose sum is σ = 21118008. Its totient is φ = 21118006.

The previous prime is 21118001. The next prime is 21118021. The reversal of 21118007 is 70081112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21118007 - 2⁴ = 21117991 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21118007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21118001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10559003 + 10559004.

It is an arithmetic number, because the mean of its divisors is an integer number (10559004).

Almost surely, 2^21118007 is an apocalyptic number.

21118007 is a deficient number, since it is larger than the sum of its proper divisors (1).

21118007 is an equidigital number, since it uses as much as digits as its factorization.

21118007 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 112, while the sum is 20.

The square root of 21118007 is about 4595.4332766345. The cubic root of 21118007 is about 276.4082341836.

Adding to 21118007 its reverse (70081112), we get a palindrome (91199119).

The spelling of 21118007 in words is "twenty-one million, one hundred eighteen thousand, seven".