545421531521 has 4 divisors (see below), whose sum is σ = 550248270852. Its totient is φ = 540594792192.

The previous prime is 545421531511. The next prime is 545421531541. The reversal of 545421531521 is 125135124545.

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 265039632400 + 280381899121 = 514820^2 + 529511^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-545421531521 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (545421531511) 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, 2413369496 + ... + 2413369721.

It is an arithmetic number, because the mean of its divisors is an integer number (137562067713).

Almost surely, 2^545421531521 is an apocalyptic number.

It is an amenable number.

545421531521 is a deficient number, since it is larger than the sum of its proper divisors (4826739331).

545421531521 is a wasteful number, since it uses less digits than its factorization.

545421531521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4826739330.

The product of its digits is 120000, while the sum is 38.

The spelling of 545421531521 in words is "five hundred forty-five billion, four hundred twenty-one million, five hundred thirty-one thousand, five hundred twenty-one".