1109661 has 16 divisors (see below), whose sum is σ = 1724544. Its totient is φ = 621504.

The previous prime is 1109653. The next prime is 1109663. The reversal of 1109661 is 1669011.

It is not a de Polignac number, because 1109661 - 2³ = 1109653 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1109663) 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, 615 + ... + 1611.

It is an arithmetic number, because the mean of its divisors is an integer number (107784).

2^1109661 is an apocalyptic number.

It is an amenable number.

1109661 is a deficient number, since it is larger than the sum of its proper divisors (614883).

1109661 is an equidigital number, since it uses as much as digits as its factorization.

1109661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1060.

The product of its (nonzero) digits is 324, while the sum is 24.

The square root of 1109661 is about 1053.4044807195. The cubic root of 1109661 is about 103.5293389252.

It can be divided in two parts, 1109 and 661, that added together give a triangular number (1770 = T₅₉).

The spelling of 1109661 in words is "one million, one hundred nine thousand, six hundred sixty-one".