21012112112123 has 16 divisors (see below), whose sum is σ = 23662868047872. Its totient is φ = 18484842600000.

The previous prime is 21012112112099. The next prime is 21012112112137. The reversal of 21012112112123 is 32121121121012.

It is a cyclic number.

It is not a de Polignac number, because 21012112112123 - 2⁸ = 21012112111867 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21012112112095 and 21012112112104.

It is not an unprimeable number, because it can be changed into a prime (21012112112143) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5694290 + ... + 8628392.

It is an arithmetic number, because the mean of its divisors is an integer number (1478929252992).

Almost surely, 2^{21012112112123} is an apocalyptic number.

21012112112123 is a deficient number, since it is larger than the sum of its proper divisors (2650755935749).

21012112112123 is a wasteful number, since it uses less digits than its factorization.

21012112112123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2955146.

The product of its (nonzero) digits is 96, while the sum is 20.

Adding to 21012112112123 its reverse (32121121121012), we get a palindrome (53133233233135).

The spelling of 21012112112123 in words is "twenty-one trillion, twelve billion, one hundred twelve million, one hundred twelve thousand, one hundred twenty-three".