21013311133123 has 4 divisors (see below), whose sum is σ = 21030924974328. Its totient is φ = 20995697291920.

The previous prime is 21013311133103. The next prime is 21013311133159. The reversal of 21013311133123 is 32133111331012.

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 21013311133123 - 2¹³ = 21013311124931 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21013311133103) 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, 8806918813 + ... + 8806921198.

It is an arithmetic number, because the mean of its divisors is an integer number (5257731243582).

Almost surely, 2^{21013311133123} is an apocalyptic number.

21013311133123 is a deficient number, since it is larger than the sum of its proper divisors (17613841205).

21013311133123 is a wasteful number, since it uses less digits than its factorization.

21013311133123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17613841204.

The product of its (nonzero) digits is 972, while the sum is 25.

Adding to 21013311133123 its reverse (32133111331012), we get a palindrome (53146422464135).

The spelling of 21013311133123 in words is "twenty-one trillion, thirteen billion, three hundred eleven million, one hundred thirty-three thousand, one hundred twenty-three".