1998151 has 4 divisors (see below), whose sum is σ = 2002192. Its totient is φ = 1994112.

The previous prime is 1998133. The next prime is 1998169. The reversal of 1998151 is 1518991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1518991 = 29 ⋅52379.

It is an interprime number because it is at equal distance from previous prime (1998133) and next prime (1998169).

It is not a de Polignac number, because 1998151 - 2⁵ = 1998119 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 (1998181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1155 + ... + 2308.

It is an arithmetic number, because the mean of its divisors is an integer number (500548).

2^1998151 is an apocalyptic number.

1998151 is a deficient number, since it is larger than the sum of its proper divisors (4041).

1998151 is an equidigital number, since it uses as much as digits as its factorization.

1998151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4040.

The product of its digits is 3240, while the sum is 34.

The square root of 1998151 is about 1413.5596909929. The cubic root of 1998151 is about 125.9532664513.

The spelling of 1998151 in words is "one million, nine hundred ninety-eight thousand, one hundred fifty-one".