661502 has 8 divisors (see below), whose sum is σ = 1001376. Its totient is φ = 327712.

The previous prime is 661483. The next prime is 661513. The reversal of 661502 is 205166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an Ulam number.

It is a congruent number.

It is an unprimeable number.

661502 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 (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1238 + ... + 1689.

It is an arithmetic number, because the mean of its divisors is an integer number (125172).

2⁶⁶¹⁵⁰² is an apocalyptic number.

661502 is a deficient number, since it is larger than the sum of its proper divisors (339874).

661502 is a wasteful number, since it uses less digits than its factorization.

661502 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3042.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 661502 is about 813.3277322212. The cubic root of 661502 is about 87.1318738157.

Adding to 661502 its reverse (205166), we get a palindrome (866668).

The spelling of 661502 in words is "six hundred sixty-one thousand, five hundred two".