21530541134121 has 4 divisors (see below), whose sum is σ = 28707388178832. Its totient is φ = 14353694089412.

The previous prime is 21530541134083. The next prime is 21530541134131. The reversal of 21530541134121 is 12143114503512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21530541134121 - 2¹⁴ = 21530541117737 is a prime.

It is a super-4 number, since 4×21530541134121⁴ (a number of 54 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (21530541134131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3588423522351 + ... + 3588423522356.

It is an arithmetic number, because the mean of its divisors is an integer number (7176847044708).

Almost surely, 2^{21530541134121} is an apocalyptic number.

It is an amenable number.

21530541134121 is a deficient number, since it is larger than the sum of its proper divisors (7176847044711).

21530541134121 is an equidigital number, since it uses as much as digits as its factorization.

21530541134121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7176847044710.

The product of its (nonzero) digits is 14400, while the sum is 33.

Adding to 21530541134121 its reverse (12143114503512), we get a palindrome (33673655637633).

It can be divided in two parts, 21530 and 541134121, that added together give a triangular number (541155651 = T₃₂₈₉₈).

The spelling of 21530541134121 in words is "twenty-one trillion, five hundred thirty billion, five hundred forty-one million, one hundred thirty-four thousand, one hundred twenty-one".