1661101 has 6 divisors (see below), whose sum is σ = 1798890. Its totient is φ = 1533168.

The previous prime is 1661069. The next prime is 1661111. The reversal of 1661101 is 1011661.

It can be written as a sum of positive squares in 3 ways, for example, as 96100 + 1565001 = 310^2 + 1251^2 .

It is not a de Polignac number, because 1661101 - 2⁵ = 1661069 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4746 + ... + 5083.

It is an arithmetic number, because the mean of its divisors is an integer number (299815).

2^1661101 is an apocalyptic number.

It is an amenable number.

1661101 is a deficient number, since it is larger than the sum of its proper divisors (137789).

1661101 is an equidigital number, since it uses as much as digits as its factorization.

1661101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9855 (or 9842 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 1661101 is about 1288.8370727132. The cubic root of 1661101 is about 118.4309864190.

Adding to 1661101 its reverse (1011661), we get a palindrome (2672762).

It can be divided in two parts, 1661 and 101, that multiplied together give a palindrome (167761).

The spelling of 1661101 in words is "one million, six hundred sixty-one thousand, one hundred one".