21117001 has 2 divisors, whose sum is σ = 21117002. Its totient is φ = 21117000.

The previous prime is 21116987. The next prime is 21117007. The reversal of 21117001 is 10071112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16605625 + 4511376 = 4075^2 + 2124^2 .

It is a cyclic number.

It is not a de Polignac number, because 21117001 - 2⁵ = 21116969 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21117007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10558500 + 10558501.

It is an arithmetic number, because the mean of its divisors is an integer number (10558501).

Almost surely, 2^21117001 is an apocalyptic number.

It is an amenable number.

21117001 is a deficient number, since it is larger than the sum of its proper divisors (1).

21117001 is an equidigital number, since it uses as much as digits as its factorization.

21117001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14, while the sum is 13.

The square root of 21117001 is about 4595.3238188402. The cubic root of 21117001 is about 276.4038450210.

Adding to 21117001 its reverse (10071112), we get a palindrome (31188113).

The spelling of 21117001 in words is "twenty-one million, one hundred seventeen thousand, one".