21003012023123 has 4 divisors (see below), whose sum is σ = 22618628332608. Its totient is φ = 19387395713640.

The previous prime is 21003012023093. The next prime is 21003012023131. The reversal of 21003012023123 is 32132021030012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21003012023123 - 2¹⁸ = 21003011760979 is a prime.

It is a super-2 number, since 2×21003012023123² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21003012023095 and 21003012023104.

It is not an unprimeable number, because it can be changed into a prime (21003012023153) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 807808154723 + ... + 807808154748.

It is an arithmetic number, because the mean of its divisors is an integer number (5654657083152).

Almost surely, 2^{21003012023123} is an apocalyptic number.

21003012023123 is a deficient number, since it is larger than the sum of its proper divisors (1615616309485).

21003012023123 is a wasteful number, since it uses less digits than its factorization.

21003012023123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1615616309484.

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 21003012023123 its reverse (32132021030012), we get a palindrome (53135033053135).

The spelling of 21003012023123 in words is "twenty-one trillion, three billion, twelve million, twenty-three thousand, one hundred twenty-three".