21613511123 has 16 divisors (see below), whose sum is σ = 23934528000. Its totient is φ = 19434778272.

The previous prime is 21613511111. The next prime is 21613511159. The reversal of 21613511123 is 32111531612.

It is not a de Polignac number, because 21613511123 - 2¹⁶ = 21613445587 is a prime.

It is a super-2 number, since 2×21613511123² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21613511092 and 21613511101.

It is not an unprimeable number, because it can be changed into a prime (21613531123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 299915 + ... + 364932.

It is an arithmetic number, because the mean of its divisors is an integer number (1495908000).

Almost surely, 2^21613511123 is an apocalyptic number.

21613511123 is a deficient number, since it is larger than the sum of its proper divisors (2321016877).

21613511123 is a wasteful number, since it uses less digits than its factorization.

21613511123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664954.

The product of its digits is 1080, while the sum is 26.

The spelling of 21613511123 in words is "twenty-one billion, six hundred thirteen million, five hundred eleven thousand, one hundred twenty-three".