1999090 has 8 divisors (see below), whose sum is σ = 3598380. Its totient is φ = 799632.

The previous prime is 1999069. The next prime is 1999099. The reversal of 1999090 is 909991.

It can be written as a sum of positive squares in 2 ways, for example, as 1825201 + 173889 = 1351^2 + 417^2 .

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

It is not an unprimeable number, because it can be changed into a prime (1999099) 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, 99945 + ... + 99964.

2^1999090 is an apocalyptic number.

1999090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1999090 is a deficient number, since it is larger than the sum of its proper divisors (1599290).

1999090 is a wasteful number, since it uses less digits than its factorization.

1999090 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199916.

The product of its (nonzero) digits is 6561, while the sum is 37.

The square root of 1999090 is about 1413.8917921821. The cubic root of 1999090 is about 125.9729932880.

The spelling of 1999090 in words is "one million, nine hundred ninety-nine thousand, ninety".