1661493 has 16 divisors (see below), whose sum is σ = 2362880. Its totient is φ = 1035504.

The previous prime is 1661489. The next prime is 1661503. The reversal of 1661493 is 3941661.

It is not a de Polignac number, because 1661493 - 2² = 1661489 is a prime.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1661493.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661293) 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 15 ways as a sum of consecutive naturals, for example, 5730 + ... + 6012.

It is an arithmetic number, because the mean of its divisors is an integer number (147680).

2^1661493 is an apocalyptic number.

It is an amenable number.

1661493 is a deficient number, since it is larger than the sum of its proper divisors (701387).

1661493 is a wasteful number, since it uses less digits than its factorization.

1661493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408.

The product of its digits is 3888, while the sum is 30.

The square root of 1661493 is about 1288.9891388216. The cubic root of 1661493 is about 118.4403017858.

The spelling of 1661493 in words is "one million, six hundred sixty-one thousand, four hundred ninety-three".