1155998 has 16 divisors (see below), whose sum is σ = 1890000. Its totient is φ = 528192.

The previous prime is 1155997. The next prime is 1156009. The reversal of 1155998 is 8995511.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1155997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 578 + ... + 1626.

It is an arithmetic number, because the mean of its divisors is an integer number (118125).

2^1155998 is an apocalyptic number.

1155998 is a deficient number, since it is larger than the sum of its proper divisors (734002).

1155998 is a wasteful number, since it uses less digits than its factorization.

1155998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1099.

The product of its digits is 16200, while the sum is 38.

The square root of 1155998 is about 1075.1734743752. The cubic root of 1155998 is about 104.9507857044.

Subtracting from 1155998 its sum of digits (38), we obtain a triangular number (1155960 = T₁₅₂₀).

The spelling of 1155998 in words is "one million, one hundred fifty-five thousand, nine hundred ninety-eight".