1205853521 has 4 divisors (see below), whose sum is σ = 1211029092. Its totient is φ = 1200677952.

The previous prime is 1205853511. The next prime is 1205853527. The reversal of 1205853521 is 1253585021.

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 273406225 + 932447296 = 16535^2 + 30536^2 .

It is a cyclic number.

It is not a de Polignac number, because 1205853521 - 2¹⁴ = 1205837137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1205853527) 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, 2587436 + ... + 2587901.

It is an arithmetic number, because the mean of its divisors is an integer number (302757273).

Almost surely, 2^1205853521 is an apocalyptic number.

It is an amenable number.

1205853521 is a deficient number, since it is larger than the sum of its proper divisors (5175571).

1205853521 is an equidigital number, since it uses as much as digits as its factorization.

1205853521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5175570.

The product of its (nonzero) digits is 12000, while the sum is 32.

The square root of 1205853521 is about 34725.4016679433. The cubic root of 1205853521 is about 1064.3836268239.

The spelling of 1205853521 in words is "one billion, two hundred five million, eight hundred fifty-three thousand, five hundred twenty-one".