661602 has 16 divisors (see below), whose sum is σ = 1366272. Its totient is φ = 213360.

The previous prime is 661553. The next prime is 661603. The reversal of 661602 is 206166.

661602 is nontrivially palindromic in base 8.

It is a super-4 number, since 4×661602⁴ (a number of 24 digits) contains 4444 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661603) by changing a digit.

661602 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 (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1593 + ... + 1964.

It is an arithmetic number, because the mean of its divisors is an integer number (85392).

2⁶⁶¹⁶⁰² is an apocalyptic number.

661602 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

661602 is an abundant number, since it is smaller than the sum of its proper divisors (704670).

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

661602 is a wasteful number, since it uses less digits than its factorization.

661602 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3593.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 661602 is about 813.3892057312. The cubic root of 661602 is about 87.1362642022.

Adding to 661602 its reverse (206166), we get a palindrome (867768).

The spelling of 661602 in words is "six hundred sixty-one thousand, six hundred two".