2154531423521 has 4 divisors (see below), whose sum is σ = 2162914814532. Its totient is φ = 2146148032512.

The previous prime is 2154531423511. The next prime is 2154531423559. The reversal of 2154531423521 is 1253241354512.

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 1025601798400 + 1128929625121 = 1012720^2 + 1062511^2 .

It is a cyclic number.

It is not a de Polignac number, because 2154531423521 - 2³⁴ = 2137351554337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2154531423511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4191695120 + ... + 4191695633.

It is an arithmetic number, because the mean of its divisors is an integer number (540728703633).

Almost surely, 2^{2154531423521} is an apocalyptic number.

It is an amenable number.

2154531423521 is a deficient number, since it is larger than the sum of its proper divisors (8383391011).

2154531423521 is an equidigital number, since it uses as much as digits as its factorization.

2154531423521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8383391010.

The product of its digits is 144000, while the sum is 38.

The spelling of 2154531423521 in words is "two trillion, one hundred fifty-four billion, five hundred thirty-one million, four hundred twenty-three thousand, five hundred twenty-one".