1998550517401 has 9 divisors (see below), whose sum is σ = 2005076138709. Its totient is φ = 1992046079100.

The previous prime is 1998550517393. The next prime is 1998550517419. The reversal of 1998550517401 is 1047150558991.

The square root of 1998550517401 is 1413701.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 1998550517401 - 2³ = 1998550517393 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1998550517101) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 467932896 + ... + 467937166.

Almost surely, 2^{1998550517401} is an apocalyptic number.

1998550517401 is the 1413701-st square number.

1998550517401 is the 706851-st centered octagonal number.

It is an amenable number.

1998550517401 is a deficient number, since it is larger than the sum of its proper divisors (6525621308).

1998550517401 is an frugal number, since it uses more digits than its factorization.

1998550517401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9204 (or 4602 counting only the distinct ones).

The product of its (nonzero) digits is 2268000, while the sum is 55.

The spelling of 1998550517401 in words is "one trillion, nine hundred ninety-eight billion, five hundred fifty million, five hundred seventeen thousand, four hundred one".