21128769167 has 16 divisors (see below), whose sum is σ = 23252741280. Its totient is φ = 19197492160.

The previous prime is 21128769149. The next prime is 21128769173. The reversal of 21128769167 is 76196782112.

It is a happy number.

It is not a de Polignac number, because 21128769167 - 2¹⁴ = 21128752783 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21128769667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3501509 + ... + 3507537.

It is an arithmetic number, because the mean of its divisors is an integer number (1453296330).

Almost surely, 2^21128769167 is an apocalyptic number.

21128769167 is a deficient number, since it is larger than the sum of its proper divisors (2123972113).

21128769167 is an equidigital number, since it uses as much as digits as its factorization.

21128769167 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8695 (or 8673 counting only the distinct ones).

The product of its digits is 508032, while the sum is 50.

The spelling of 21128769167 in words is "twenty-one billion, one hundred twenty-eight million, seven hundred sixty-nine thousand, one hundred sixty-seven".