661268 has 6 divisors (see below), whose sum is σ = 1157226. Its totient is φ = 330632.

The previous prime is 661267. The next prime is 661321. The reversal of 661268 is 862166.

It can be written as a sum of positive squares in only one way, i.e., 334084 + 327184 = 578^2 + 572^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 661268.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82655 + ... + 82662.

It is an arithmetic number, because the mean of its divisors is an integer number (192871).

2⁶⁶¹²⁶⁸ is an apocalyptic number.

It is an amenable number.

661268 is a deficient number, since it is larger than the sum of its proper divisors (495958).

661268 is a wasteful number, since it uses less digits than its factorization.

661268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165321 (or 165319 counting only the distinct ones).

The product of its digits is 3456, while the sum is 29.

The square root of 661268 is about 813.1838660475. The cubic root of 661268 is about 87.1215985819.

It can be divided in two parts, 661 and 268, that added together give a palindrome (929).

The spelling of 661268 in words is "six hundred sixty-one thousand, two hundred sixty-eight".