661016 has 16 divisors (see below), whose sum is σ = 1263600. Its totient is φ = 324064.

The previous prime is 661009. The next prime is 661019. The reversal of 661016 is 610166.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 661016.

It is not an unprimeable number, because it can be changed into a prime (661019) by changing a digit.

661016 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 356 + ... + 1203.

It is an arithmetic number, because the mean of its divisors is an integer number (78975).

2⁶⁶¹⁰¹⁶ is an apocalyptic number.

It is an amenable number.

661016 is a deficient number, since it is larger than the sum of its proper divisors (602584).

661016 is a wasteful number, since it uses less digits than its factorization.

661016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1618 (or 1614 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 661016 is about 813.0289047752. The cubic root of 661016 is about 87.1105302343.

The spelling of 661016 in words is "six hundred sixty-one thousand, sixteen".