1997555585 has 4 divisors (see below), whose sum is σ = 2397066708. Its totient is φ = 1598044464.

The previous prime is 1997555569. The next prime is 1997555603. The reversal of 1997555585 is 5855557991.

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 971506561 + 1026049024 = 31169^2 + 32032^2 .

It is a cyclic number.

It is not a de Polignac number, because 1997555585 - 2⁴ = 1997555569 is a prime.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 199755554 + ... + 199755563.

It is an arithmetic number, because the mean of its divisors is an integer number (599266677).

Almost surely, 2^1997555585 is an apocalyptic number.

It is an amenable number.

1997555585 is a deficient number, since it is larger than the sum of its proper divisors (399511123).

1997555585 is an equidigital number, since it uses as much as digits as its factorization.

1997555585 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 399511122.

The product of its digits is 14175000, while the sum is 59.

The square root of 1997555585 is about 44694.0218038162. The cubic root of 1997555585 is about 1259.4075456496.

The spelling of 1997555585 in words is "one billion, nine hundred ninety-seven million, five hundred fifty-five thousand, five hundred eighty-five".