21011133123 has 12 divisors (see below), whose sum is σ = 30351248928. Its totient is φ = 14006575440.

The previous prime is 21011133079. The next prime is 21011133137. The reversal of 21011133123 is 32133111012.

It is not a de Polignac number, because 21011133123 - 2¹⁶ = 21011067587 is a prime.

It is a super-2 number, since 2×21011133123² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21011133096 and 21011133105.

It is not an unprimeable number, because it can be changed into a prime (21011133193) 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 11 ways as a sum of consecutive naturals, for example, 111286 + ... + 233252.

It is an arithmetic number, because the mean of its divisors is an integer number (2529270744).

Almost surely, 2^21011133123 is an apocalyptic number.

21011133123 is a deficient number, since it is larger than the sum of its proper divisors (9340115805).

21011133123 is a wasteful number, since it uses less digits than its factorization.

21011133123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141114 (or 141111 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

Adding to 21011133123 its reverse (32133111012), we get a palindrome (53144244135).

The spelling of 21011133123 in words is "twenty-one billion, eleven million, one hundred thirty-three thousand, one hundred twenty-three".