1081999 has 4 divisors (see below), whose sum is σ = 1145664. Its totient is φ = 1018336.

The previous prime is 1081981. The next prime is 1082017. The reversal of 1081999 is 9991801.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9991801 = 17 ⋅587753.

It is an interprime number because it is at equal distance from previous prime (1081981) and next prime (1082017).

It is a cyclic number.

It is not a de Polignac number, because 1081999 - 2¹⁷ = 950927 is a prime.

It is an Ulam number.

1081999 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1081919) 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, 31807 + ... + 31840.

It is an arithmetic number, because the mean of its divisors is an integer number (286416).

2^1081999 is an apocalyptic number.

1081999 is a deficient number, since it is larger than the sum of its proper divisors (63665).

1081999 is an equidigital number, since it uses as much as digits as its factorization.

1081999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63664.

The product of its (nonzero) digits is 5832, while the sum is 37.

The square root of 1081999 is about 1040.1918092352. The cubic root of 1081999 is about 102.6618185619.

It can be divided in two parts, 1081 and 999, that added together give a triangular number (2080 = T₆₄).

The spelling of 1081999 in words is "one million, eighty-one thousand, nine hundred ninety-nine".