21142120117 has 2 divisors, whose sum is σ = 21142120118. Its totient is φ = 21142120116.

The previous prime is 21142120093. The next prime is 21142120123. The reversal of 21142120117 is 71102124112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14046753361 + 7095366756 = 118519^2 + 84234^2 .

It is a cyclic number.

It is not a de Polignac number, because 21142120117 - 2¹⁹ = 21141595829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21142120157) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571060058 + 10571060059.

It is an arithmetic number, because the mean of its divisors is an integer number (10571060059).

Almost surely, 2^21142120117 is an apocalyptic number.

It is an amenable number.

21142120117 is a deficient number, since it is larger than the sum of its proper divisors (1).

21142120117 is an equidigital number, since it uses as much as digits as its factorization.

21142120117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 224, while the sum is 22.

Adding to 21142120117 its reverse (71102124112), we get a palindrome (92244244229).

The spelling of 21142120117 in words is "twenty-one billion, one hundred forty-two million, one hundred twenty thousand, one hundred seventeen".