1980645545 has 8 divisors (see below), whose sum is σ = 2377074120. Its totient is φ = 1584316800.

The previous prime is 1980645479. The next prime is 1980645553. The reversal of 1980645545 is 5455460891.

It can be written as a sum of positive squares in 4 ways, for example, as 1387041049 + 593604496 = 37243^2 + 24364^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1980645545 - 2²⁸ = 1712210089 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1980645545.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29501 + ... + 69509.

It is an arithmetic number, because the mean of its divisors is an integer number (297134265).

Almost surely, 2^1980645545 is an apocalyptic number.

It is an amenable number.

1980645545 is a deficient number, since it is larger than the sum of its proper divisors (396428575).

1980645545 is an equidigital number, since it uses as much as digits as its factorization.

1980645545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49915.

The product of its (nonzero) digits is 864000, while the sum is 47.

The square root of 1980645545 is about 44504.4441039319. Note that the first 3 decimals coincide. The cubic root of 1980645545 is about 1255.8436880762.

The spelling of 1980645545 in words is "one billion, nine hundred eighty million, six hundred forty-five thousand, five hundred forty-five".