21001192117 has 2 divisors, whose sum is σ = 21001192118. Its totient is φ = 21001192116.

The previous prime is 21001192067. The next prime is 21001192237. The reversal of 21001192117 is 71129110012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12031018596 + 8970173521 = 109686^2 + 94711^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001192117 - 2²³ = 20992803509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21001192091 and 21001192100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21001192717) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500596058 + 10500596059.

It is an arithmetic number, because the mean of its divisors is an integer number (10500596059).

Almost surely, 2^21001192117 is an apocalyptic number.

It is an amenable number.

21001192117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001192117 is an equidigital number, since it uses as much as digits as its factorization.

21001192117 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252, while the sum is 25.

The spelling of 21001192117 in words is "twenty-one billion, one million, one hundred ninety-two thousand, one hundred seventeen".