21092117 has 2 divisors, whose sum is σ = 21092118. Its totient is φ = 21092116.

The previous prime is 21092101. The next prime is 21092119. The reversal of 21092117 is 71129012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16313521 + 4778596 = 4039^2 + 2186^2 .

It is a cyclic number.

It is not a de Polignac number, because 21092117 - 2⁴ = 21092101 is a prime.

Together with 21092119, 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 = 21092092 and 21092101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21092119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10546058 + 10546059.

It is an arithmetic number, because the mean of its divisors is an integer number (10546059).

Almost surely, 2^21092117 is an apocalyptic number.

It is an amenable number.

21092117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21092117 is an equidigital number, since it uses as much as digits as its factorization.

21092117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 252, while the sum is 23.

The square root of 21092117 is about 4592.6154857554. The cubic root of 21092117 is about 276.2952321122.

The spelling of 21092117 in words is "twenty-one million, ninety-two thousand, one hundred seventeen".