21123141355533 has 16 divisors (see below), whose sum is σ = 32187950236800. Its totient is φ = 12070251638976.

The previous prime is 21123141355471. The next prime is 21123141355577. The reversal of 21123141355533 is 33555314132112.

It is a happy number.

It is not a de Polignac number, because 21123141355533 - 2⁶ = 21123141355469 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21123141355491 and 21123141355500.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123141356533) 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, 2500458 + ... + 6964091.

It is an arithmetic number, because the mean of its divisors is an integer number (2011746889800).

Almost surely, 2^{21123141355533} is an apocalyptic number.

It is an amenable number.

21123141355533 is a deficient number, since it is larger than the sum of its proper divisors (11064808881267).

21123141355533 is a wasteful number, since it uses less digits than its factorization.

21123141355533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9570836.

The product of its digits is 162000, while the sum is 39.

Adding to 21123141355533 its reverse (33555314132112), we get a palindrome (54678455487645).

The spelling of 21123141355533 in words is "twenty-one trillion, one hundred twenty-three billion, one hundred forty-one million, three hundred fifty-five thousand, five hundred thirty-three".