1999081 has 16 divisors (see below), whose sum is σ = 2457216. Its totient is φ = 1587456.

The previous prime is 1999069. The next prime is 1999099. The reversal of 1999081 is 1809991.

It is a cyclic number.

It is not a de Polignac number, because 1999081 - 2⁹ = 1998569 is a prime.

It is a super-2 number, since 2×1999081² = 7992649689122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1999081.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12655 + ... + 12811.

It is an arithmetic number, because the mean of its divisors is an integer number (153576).

2^1999081 is an apocalyptic number.

It is an amenable number.

1999081 is a deficient number, since it is larger than the sum of its proper divisors (458135).

1999081 is a wasteful number, since it uses less digits than its factorization.

1999081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288.

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

The square root of 1999081 is about 1413.8886094739. Note that the first 3 decimals coincide. The cubic root of 1999081 is about 125.9728042422.

The spelling of 1999081 in words is "one million, nine hundred ninety-nine thousand, eighty-one".