1661872 has 10 divisors (see below), whose sum is σ = 3219908. Its totient is φ = 830928.

The previous prime is 1661861. The next prime is 1661887. The reversal of 1661872 is 2781661.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 51918 + ... + 51949.

2^1661872 is an apocalyptic number.

It is an amenable number.

1661872 is a deficient number, since it is larger than the sum of its proper divisors (1558036).

1661872 is a wasteful number, since it uses less digits than its factorization.

1661872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103875 (or 103869 counting only the distinct ones).

The product of its digits is 4032, while the sum is 31.

The square root of 1661872 is about 1289.1361448660. The cubic root of 1661872 is about 118.4493068316.

The spelling of 1661872 in words is "one million, six hundred sixty-one thousand, eight hundred seventy-two".