661782 has 32 divisors (see below), whose sum is σ = 1488384. Its totient is φ = 194400.

The previous prime is 661777. The next prime is 661823. The reversal of 661782 is 287166.

It is a happy number.

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 661782.

It is an unprimeable number.

661782 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, 2307 + ... + 2577.

It is an arithmetic number, because the mean of its divisors is an integer number (46512).

2⁶⁶¹⁷⁸² is an apocalyptic number.

It is a pronic number, being equal to 813×814.

It is a practical number, because each smaller number is the sum of distinct divisors of 661782, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (744192).

661782 is an abundant number, since it is smaller than the sum of its proper divisors (826602).

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

661782 is a wasteful number, since it uses less digits than its factorization.

661782 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 324.

The product of its digits is 4032, while the sum is 30.

The square root of 661782 is about 813.4998463429. The cubic root of 661782 is about 87.1441657832.

The spelling of 661782 in words is "six hundred sixty-one thousand, seven hundred eighty-two".