21049316123 has 24 divisors (see below), whose sum is σ = 24005555280. Its totient is φ = 18282808320.

The previous prime is 21049316087. The next prime is 21049316137. The reversal of 21049316123 is 32161394012.

It is not a de Polignac number, because 21049316123 - 2²⁰ = 21048267547 is a prime.

It is a super-2 number, since 2×21049316123² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21049316123.

It is not an unprimeable number, because it can be changed into a prime (21049316153) 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 in 23 ways as a sum of consecutive naturals, for example, 2997965 + ... + 3004977.

It is an arithmetic number, because the mean of its divisors is an integer number (1000231470).

Almost surely, 2^21049316123 is an apocalyptic number.

21049316123 is a deficient number, since it is larger than the sum of its proper divisors (2956239157).

21049316123 is an equidigital number, since it uses as much as digits as its factorization.

21049316123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7247 (or 7150 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 32.

The spelling of 21049316123 in words is "twenty-one billion, forty-nine million, three hundred sixteen thousand, one hundred twenty-three".