668776 has 8 divisors (see below), whose sum is σ = 1253970. Its totient is φ = 334384.

The previous prime is 668761. The next prime is 668791. The reversal of 668776 is 677866.

It is an interprime number because it is at equal distance from previous prime (668761) and next prime (668791).

It can be written as a sum of positive squares in only one way, i.e., 562500 + 106276 = 750^2 + 326^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×668776² = 894522676352, which contains 22 as substring.

It is an unprimeable number.

668776 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 as a sum of consecutive naturals, namely, 41791 + ... + 41806.

2⁶⁶⁸⁷⁷⁶ is an apocalyptic number.

It is an amenable number.

668776 is a deficient number, since it is larger than the sum of its proper divisors (585194).

668776 is a wasteful number, since it uses less digits than its factorization.

668776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83603 (or 83599 counting only the distinct ones).

The product of its digits is 84672, while the sum is 40.

The square root of 668776 is about 817.7872583992. The cubic root of 668776 is about 87.4500830935.

It can be divided in two parts, 668 and 776, that added together give a square (1444 = 38²).

The spelling of 668776 in words is "six hundred sixty-eight thousand, seven hundred seventy-six".