21493162069 has 2 divisors, whose sum is σ = 21493162070. Its totient is φ = 21493162068.

The previous prime is 21493162037. The next prime is 21493162091. The reversal of 21493162069 is 96026139412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17546181444 + 3946980625 = 132462^2 + 62825^2 .

It is a cyclic number.

It is not a de Polignac number, because 21493162069 - 2⁵ = 21493162037 is a prime.

It is a super-2 number, since 2×21493162069² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21493162969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10746581034 + 10746581035.

It is an arithmetic number, because the mean of its divisors is an integer number (10746581035).

Almost surely, 2^21493162069 is an apocalyptic number.

It is an amenable number.

21493162069 is a deficient number, since it is larger than the sum of its proper divisors (1).

21493162069 is an equidigital number, since it uses as much as digits as its factorization.

21493162069 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 139968, while the sum is 43.

The spelling of 21493162069 in words is "twenty-one billion, four hundred ninety-three million, one hundred sixty-two thousand, sixty-nine".