661086 has 24 divisors (see below), whose sum is σ = 1508520. Its totient is φ = 208656.

The previous prime is 661061. The next prime is 661091. The reversal of 661086 is 680166.

661086 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

661086 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 625 + ... + 1308.

It is an arithmetic number, because the mean of its divisors is an integer number (62855).

2⁶⁶¹⁰⁸⁶ is an apocalyptic number.

661086 is an abundant number, since it is smaller than the sum of its proper divisors (847434).

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

661086 is a wasteful number, since it uses less digits than its factorization.

661086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1960 (or 1957 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 661086 is about 813.0719525356. The cubic root of 661086 is about 87.1136050574.

The spelling of 661086 in words is "six hundred sixty-one thousand, eighty-six".