611661 has 8 divisors (see below), whose sum is σ = 841984. Its totient is φ = 394560.

The previous prime is 611657. The next prime is 611671. The reversal of 611661 is 166116.

611661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 611661 - 2² = 611657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (611621) 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, 3196 + ... + 3381.

It is an arithmetic number, because the mean of its divisors is an integer number (105248).

2⁶¹¹⁶⁶¹ is an apocalyptic number.

It is an amenable number.

611661 is a deficient number, since it is larger than the sum of its proper divisors (230323).

611661 is a wasteful number, since it uses less digits than its factorization.

611661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6611.

The product of its digits is 216, while the sum is 21.

The square root of 611661 is about 782.0875910024. The cubic root of 611661 is about 84.8861682709.

Adding to 611661 its reverse (166116), we get a palindrome (777777).

The spelling of 611661 in words is "six hundred eleven thousand, six hundred sixty-one".