1661718 has 8 divisors (see below), whose sum is σ = 3323448. Its totient is φ = 553904.

The previous prime is 1661713. The next prime is 1661731. The reversal of 1661718 is 8171661.

It is a happy number.

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

1661718 is an admirable number.

It is a super-2 number, since 2×1661718² = 5522613423048, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661713) 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 3 ways as a sum of consecutive naturals, for example, 138471 + ... + 138482.

It is an arithmetic number, because the mean of its divisors is an integer number (415431).

2^1661718 is an apocalyptic number.

1661718 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1661718 is a wasteful number, since it uses less digits than its factorization.

1661718 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276958.

The product of its digits is 2016, while the sum is 30.

The square root of 1661718 is about 1289.0764135613. The cubic root of 1661718 is about 118.4456479544.

The spelling of 1661718 in words is "one million, six hundred sixty-one thousand, seven hundred eighteen".