1661002 has 24 divisors (see below), whose sum is σ = 3071844. Its totient is φ = 669312.

The previous prime is 1660963. The next prime is 1661003. The reversal of 1661002 is 2001661.

It can be written as a sum of positive squares in 2 ways, for example, as 1466521 + 194481 = 1211^2 + 441^2 .

It is not an unprimeable number, because it can be changed into a prime (1661003) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1168 + ... + 2164.

2^1661002 is an apocalyptic number.

1661002 is a deficient number, since it is larger than the sum of its proper divisors (1410842).

1661002 is a wasteful number, since it uses less digits than its factorization.

1661002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1030 (or 1023 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 1661002 is about 1288.7986654245. The cubic root of 1661002 is about 118.4286335818.

Adding to 1661002 its reverse (2001661), we get a palindrome (3662663).

The spelling of 1661002 in words is "one million, six hundred sixty-one thousand, two".