1997948597 has 4 divisors (see below), whose sum is σ = 1998051756. Its totient is φ = 1997845440.

The previous prime is 1997948549. The next prime is 1997948611. The reversal of 1997948597 is 7958497991.

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: 7958497991 = 71 ⋅112091521.

It can be written as a sum of positive squares in 2 ways, for example, as 951167281 + 1046781316 = 30841^2 + 32354^2 .

It is a cyclic number.

It is not a de Polignac number, because 1997948597 - 2¹⁰ = 1997947573 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1997948507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12818 + ... + 64499.

It is an arithmetic number, because the mean of its divisors is an integer number (499512939).

Almost surely, 2^1997948597 is an apocalyptic number.

It is an amenable number.

1997948597 is a deficient number, since it is larger than the sum of its proper divisors (103159).

1997948597 is an equidigital number, since it uses as much as digits as its factorization.

1997948597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103158.

The product of its digits is 51438240, while the sum is 68.

The square root of 1997948597 is about 44698.4182829773. The cubic root of 1997948597 is about 1259.4901348943.

The spelling of 1997948597 in words is "one billion, nine hundred ninety-seven million, nine hundred forty-eight thousand, five hundred ninety-seven".