1003661 has 8 divisors (see below), whose sum is σ = 1059480. Its totient is φ = 949312.

The previous prime is 1003631. The next prime is 1003679. The reversal of 1003661 is 1663001.

1003661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 136900 + 866761 = 370^2 + 931^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1003661 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 (1003601) 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, 1211 + ... + 1863.

It is an arithmetic number, because the mean of its divisors is an integer number (132435).

2^1003661 is an apocalyptic number.

1003661 is the 536-th centered heptagonal number.

It is an amenable number.

1003661 is a deficient number, since it is larger than the sum of its proper divisors (55819).

1003661 is an equidigital number, since it uses as much as digits as its factorization.

1003661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 735.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 1003661 is about 1001.8288276946. The cubic root of 1003661 is about 100.1218847141.

Adding to 1003661 its reverse (1663001), we get a palindrome (2666662).

The spelling of 1003661 in words is "one million, three thousand, six hundred sixty-one".