21900192919181 has 2 divisors, whose sum is σ = 21900192919182. Its totient is φ = 21900192919180.

The previous prime is 21900192919147. The next prime is 21900192919223. The reversal of 21900192919181 is 18191929100912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12274897638025 + 9625295281156 = 3503555^2 + 3102466^2 .

It is a cyclic number.

It is not a de Polignac number, because 21900192919181 - 2¹⁸ = 21900192657037 is a prime.

It is a super-2 number, since 2×21900192919181² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21900192919141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10950096459590 + 10950096459591.

It is an arithmetic number, because the mean of its divisors is an integer number (10950096459591).

Almost surely, 2^{21900192919181} is an apocalyptic number.

It is an amenable number.

21900192919181 is a deficient number, since it is larger than the sum of its proper divisors (1).

21900192919181 is an equidigital number, since it uses as much as digits as its factorization.

21900192919181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 209952, while the sum is 53.

The spelling of 21900192919181 in words is "twenty-one trillion, nine hundred billion, one hundred ninety-two million, nine hundred nineteen thousand, one hundred eighty-one".