1998564516 has 240 divisors, whose sum is σ = 5880809088. Its totient is φ = 587865600.

The previous prime is 1998564497. The next prime is 1998564521. The reversal of 1998564516 is 6154658991.

It is a super-2 number, since 2×1998564516² = 7988520249228628512, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 12261051 + ... + 12261213.

Almost surely, 2^1998564516 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1998564516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2940404544).

1998564516 is an abundant number, since it is smaller than the sum of its proper divisors (3882244572).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1998564516 is a wasteful number, since it uses less digits than its factorization.

1998564516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304 (or 293 counting only the distinct ones).

The product of its digits is 2332800, while the sum is 54.

The square root of 1998564516 is about 44705.3074701427. The cubic root of 1998564516 is about 1259.6195449977.

The spelling of 1998564516 in words is "one billion, nine hundred ninety-eight million, five hundred sixty-four thousand, five hundred sixteen".