616661 has 4 divisors (see below), whose sum is σ = 622752. Its totient is φ = 610572.

The previous prime is 616643. The next prime is 616669. The reversal of 616661 is 166616.

616661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 616661 - 2⁶ = 616597 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 616661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (616669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2891 + ... + 3096.

It is an arithmetic number, because the mean of its divisors is an integer number (155688).

2⁶¹⁶⁶⁶¹ is an apocalyptic number.

It is an amenable number.

616661 is a deficient number, since it is larger than the sum of its proper divisors (6091).

616661 is a wasteful number, since it uses less digits than its factorization.

616661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6090.

The product of its digits is 1296, while the sum is 26.

The square root of 616661 is about 785.2776579020. The cubic root of 616661 is about 85.1168404716.

The spelling of 616661 in words is "six hundred sixteen thousand, six hundred sixty-one".