661158 has 24 divisors (see below), whose sum is σ = 1495728. Its totient is φ = 210672.

The previous prime is 661139. The next prime is 661183. The reversal of 661158 is 851166.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 385 + ... + 1212.

It is an arithmetic number, because the mean of its divisors is an integer number (62322).

2⁶⁶¹¹⁵⁸ is an apocalyptic number.

661158 is an abundant number, since it is smaller than the sum of its proper divisors (834570).

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

661158 is a wasteful number, since it uses less digits than its factorization.

661158 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1628 (or 1625 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 661158 is about 813.1162278543. The cubic root of 661158 is about 87.1167675062.

The spelling of 661158 in words is "six hundred sixty-one thousand, one hundred fifty-eight".