1099990 has 16 divisors (see below), whose sum is σ = 1991952. Its totient is φ = 437344.

The previous prime is 1099961. The next prime is 1099997. The reversal of 1099990 is 999901.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1099997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2997 + ... + 3343.

It is an arithmetic number, because the mean of its divisors is an integer number (124497).

2^1099990 is an apocalyptic number.

1099990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1099990 is a deficient number, since it is larger than the sum of its proper divisors (891962).

1099990 is a wasteful number, since it uses less digits than its factorization.

1099990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 671.

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

The square root of 1099990 is about 1048.8040808464. The cubic root of 1099990 is about 103.2276987325.

It can be divided in two parts, 10 and 99990, that added together give a 5-th power (100000 = 10⁵).

The spelling of 1099990 in words is "one million, ninety-nine thousand, nine hundred ninety".