21018075769 has 2 divisors, whose sum is σ = 21018075770. Its totient is φ = 21018075768.

The previous prime is 21018075719. The next prime is 21018075773. The reversal of 21018075769 is 96757081012.

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., 19943088400 + 1074987369 = 141220^2 + 32787^2 .

It is a cyclic number.

It is not a de Polignac number, because 21018075769 - 2¹⁵ = 21018043001 is a prime.

It is a super-2 number, since 2×21018075769² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21018075719) 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, 10509037884 + 10509037885.

It is an arithmetic number, because the mean of its divisors is an integer number (10509037885).

Almost surely, 2^21018075769 is an apocalyptic number.

It is an amenable number.

21018075769 is a deficient number, since it is larger than the sum of its proper divisors (1).

21018075769 is an equidigital number, since it uses as much as digits as its factorization.

21018075769 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 211680, while the sum is 46.

The spelling of 21018075769 in words is "twenty-one billion, eighteen million, seventy-five thousand, seven hundred sixty-nine".