1980205523 has 4 divisors (see below), whose sum is σ = 1980311928. Its totient is φ = 1980099120.

The previous prime is 1980205511. The next prime is 1980205531. The reversal of 1980205523 is 3255020891.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 3255020891 = 19 ⋅171316889.

It is a cyclic number.

It is not a de Polignac number, because 1980205523 - 2⁸ = 1980205267 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1980205223) 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, 17138 + ... + 65223.

It is an arithmetic number, because the mean of its divisors is an integer number (495077982).

Almost surely, 2^1980205523 is an apocalyptic number.

1980205523 is a deficient number, since it is larger than the sum of its proper divisors (106405).

1980205523 is an equidigital number, since it uses as much as digits as its factorization.

1980205523 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106404.

The product of its (nonzero) digits is 21600, while the sum is 35.

The square root of 1980205523 is about 44499.5002556208. The cubic root of 1980205523 is about 1255.7506813997.

The spelling of 1980205523 in words is "one billion, nine hundred eighty million, two hundred five thousand, five hundred twenty-three".