1998213512 has 8 divisors (see below), whose sum is σ = 3746650350. Its totient is φ = 999106752.

The previous prime is 1998213509. The next prime is 1998213523. The reversal of 1998213512 is 2153128991.

It can be written as a sum of positive squares in only one way, i.e., 1872639076 + 125574436 = 43274^2 + 11206^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 1998213512.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124888337 + ... + 124888352.

Almost surely, 2^1998213512 is an apocalyptic number.

It is an amenable number.

1998213512 is a deficient number, since it is larger than the sum of its proper divisors (1748436838).

1998213512 is a wasteful number, since it uses less digits than its factorization.

1998213512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249776695 (or 249776691 counting only the distinct ones).

The product of its digits is 38880, while the sum is 41.

The square root of 1998213512 is about 44701.3815446458. The cubic root of 1998213512 is about 1259.5457991698.

The spelling of 1998213512 in words is "one billion, nine hundred ninety-eight million, two hundred thirteen thousand, five hundred twelve".