1998471523591 has 8 divisors (see below), whose sum is σ = 2002283717184. Its totient is φ = 1994662881120.

The previous prime is 1998471523577. The next prime is 1998471523627. The reversal of 1998471523591 is 1953251748991.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1998471523591 - 2³³ = 1989881588999 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1998471523501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 240201 + ... + 2013613.

It is an arithmetic number, because the mean of its divisors is an integer number (250285464648).

Almost surely, 2^{1998471523591} is an apocalyptic number.

1998471523591 is a deficient number, since it is larger than the sum of its proper divisors (3812193593).

1998471523591 is a wasteful number, since it uses less digits than its factorization.

1998471523591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1775561.

The product of its digits is 24494400, while the sum is 64.

The spelling of 1998471523591 in words is "one trillion, nine hundred ninety-eight billion, four hundred seventy-one million, five hundred twenty-three thousand, five hundred ninety-one".