1998087489 has 6 divisors (see below), whose sum is σ = 2886126386. Its totient is φ = 1332058320.

The previous prime is 1998087473. The next prime is 1998087541. The reversal of 1998087489 is 9847808991.

It can be written as a sum of positive squares in only one way, i.e., 1988446464 + 9641025 = 44592^2 + 3105^2 .

It is not a de Polignac number, because 1998087489 - 2⁴ = 1998087473 is a prime.

It is a super-3 number, since 3×1998087489³ (a number of 29 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1998087449) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 111004852 + ... + 111004869.

Almost surely, 2^1998087489 is an apocalyptic number.

It is an amenable number.

1998087489 is a deficient number, since it is larger than the sum of its proper divisors (888038897).

1998087489 is a wasteful number, since it uses less digits than its factorization.

1998087489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222009727 (or 222009724 counting only the distinct ones).

The product of its (nonzero) digits is 10450944, while the sum is 63.

The square root of 1998087489 is about 44699.9719127429. The cubic root of 1998087489 is about 1259.5193196709.

The spelling of 1998087489 in words is "one billion, nine hundred ninety-eight million, eighty-seven thousand, four hundred eighty-nine".