669766 has 8 divisors (see below), whose sum is σ = 1063800. Its totient is φ = 315168.

The previous prime is 669763. The next prime is 669787. The reversal of 669766 is 667966.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669763) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9816 + ... + 9883.

It is an arithmetic number, because the mean of its divisors is an integer number (132975).

2⁶⁶⁹⁷⁶⁶ is an apocalyptic number.

669766 is a deficient number, since it is larger than the sum of its proper divisors (394034).

669766 is a wasteful number, since it uses less digits than its factorization.

669766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19718.

The product of its digits is 81648, while the sum is 40.

The square root of 669766 is about 818.3923264547. The cubic root of 669766 is about 87.4932130790.

It can be divided in two parts, 66976 and 6, that multiplied together give a triangular number (401856 = T₈₉₆).

The spelling of 669766 in words is "six hundred sixty-nine thousand, seven hundred sixty-six".