1998169497 has 24 divisors (see below), whose sum is σ = 3012876360. Its totient is φ = 1274849280.

The previous prime is 1998169489. The next prime is 1998169501. The reversal of 1998169497 is 7949618991.

1998169497 is a `hidden beast` number, since 1 + 9 + 9 + 81 + 69 + 497 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 726248601 + 1271920896 = 26949^2 + 35664^2 .

It is not a de Polignac number, because 1998169497 - 2³ = 1998169489 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1998169427) 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 23 ways as a sum of consecutive naturals, for example, 28872 + ... + 69497.

It is an arithmetic number, because the mean of its divisors is an integer number (125536515).

Almost surely, 2^1998169497 is an apocalyptic number.

It is an amenable number.

1998169497 is a deficient number, since it is larger than the sum of its proper divisors (1014706863).

1998169497 is a wasteful number, since it uses less digits than its factorization.

1998169497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98473 (or 98470 counting only the distinct ones).

The product of its digits is 8817984, while the sum is 63.

The square root of 1998169497 is about 44700.8892193433. The cubic root of 1998169497 is about 1259.5365510230.

The spelling of 1998169497 in words is "one billion, nine hundred ninety-eight million, one hundred sixty-nine thousand, four hundred ninety-seven".