1998131553 has 24 divisors (see below), whose sum is σ = 3195575136. Its totient is φ = 1192910400.

The previous prime is 1998131549. The next prime is 1998131557. The reversal of 1998131553 is 3551318991.

1998131553 is a `hidden beast` number, since 1 + 9 + 98 + 1 + 3 + 1 + 553 = 666.

It is an interprime number because it is at equal distance from previous prime (1998131549) and next prime (1998131557).

It is not a de Polignac number, because 1998131553 - 2² = 1998131549 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1998131499 and 1998131508.

It is not an unprimeable number, because it can be changed into a prime (1998131557) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 143988 + ... + 157253.

It is an arithmetic number, because the mean of its divisors is an integer number (133148964).

Almost surely, 2^1998131553 is an apocalyptic number.

It is an amenable number.

1998131553 is a deficient number, since it is larger than the sum of its proper divisors (1197443583).

1998131553 is a wasteful number, since it uses less digits than its factorization.

1998131553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 301325 (or 301322 counting only the distinct ones).

The product of its digits is 145800, while the sum is 45.

The square root of 1998131553 is about 44700.4647962412. The cubic root of 1998131553 is about 1259.5285783665.

The spelling of 1998131553 in words is "one billion, nine hundred ninety-eight million, one hundred thirty-one thousand, five hundred fifty-three".