661830 has 32 divisors (see below), whose sum is σ = 1711584. Its totient is φ = 162816.

The previous prime is 661823. The next prime is 661849. The reversal of 661830 is 38166.

It is a self number, because there is not a number n which added to its sum of digits gives 661830.

It is a congruent number.

It is an unprimeable number.

661830 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 15 ways as a sum of consecutive naturals, for example, 459 + ... + 1238.

It is an arithmetic number, because the mean of its divisors is an integer number (53487).

2⁶⁶¹⁸³⁰ is an apocalyptic number.

661830 is an abundant number, since it is smaller than the sum of its proper divisors (1049754).

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

661830 is a wasteful number, since it uses less digits than its factorization.

661830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1720.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 661830 is about 813.5293479648. The cubic root of 661830 is about 87.1462726295.

Adding to 661830 its reverse (38166), we get a palindrome (699996).

The spelling of 661830 in words is "six hundred sixty-one thousand, eight hundred thirty".