21123120012133 has 4 divisors (see below), whose sum is σ = 21129760417708. Its totient is φ = 21116479606560.

The previous prime is 21123120012103. The next prime is 21123120012217. The reversal of 21123120012133 is 33121002132112.

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

It can be written as a sum of positive squares in 2 ways, for example, as 796160029284 + 20326959982849 = 892278^2 + 4508543^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21123120012133 is a prime.

It is a super-3 number, since 3×21123120012133³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123120012103) 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, 3320198016 + ... + 3320204377.

It is an arithmetic number, because the mean of its divisors is an integer number (5282440104427).

Almost surely, 2^{21123120012133} is an apocalyptic number.

It is an amenable number.

21123120012133 is a deficient number, since it is larger than the sum of its proper divisors (6640405575).

21123120012133 is an equidigital number, since it uses as much as digits as its factorization.

21123120012133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6640405574.

The product of its (nonzero) digits is 432, while the sum is 22.

Adding to 21123120012133 its reverse (33121002132112), we get a palindrome (54244122144245).

The spelling of 21123120012133 in words is "twenty-one trillion, one hundred twenty-three billion, one hundred twenty million, twelve thousand, one hundred thirty-three".