21020331013123 has 32 divisors (see below), whose sum is σ = 23873412147200. Its totient is φ = 18347692962816.

The previous prime is 21020331013109. The next prime is 21020331013127. The reversal of 21020331013123 is 32131013302012.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21020331013123 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21020331013094 and 21020331013103.

It is not an unprimeable number, because it can be changed into a prime (21020331013127) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 451958836 + ... + 452005342.

It is an arithmetic number, because the mean of its divisors is an integer number (746044129600).

Almost surely, 2^{21020331013123} is an apocalyptic number.

21020331013123 is a deficient number, since it is larger than the sum of its proper divisors (2853081134077).

21020331013123 is a wasteful number, since it uses less digits than its factorization.

21020331013123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49931.

The product of its (nonzero) digits is 648, while the sum is 22.

Adding to 21020331013123 its reverse (32131013302012), we get a palindrome (53151344315135).

The spelling of 21020331013123 in words is "twenty-one trillion, twenty billion, three hundred thirty-one million, thirteen thousand, one hundred twenty-three".