669751 has 4 divisors (see below), whose sum is σ = 675792. Its totient is φ = 663712.

The previous prime is 669733. The next prime is 669763. The reversal of 669751 is 157966.

669751 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 669751 - 2¹⁵ = 636983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669701) 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, 2851 + ... + 3076.

It is an arithmetic number, because the mean of its divisors is an integer number (168948).

2⁶⁶⁹⁷⁵¹ is an apocalyptic number.

669751 is a deficient number, since it is larger than the sum of its proper divisors (6041).

669751 is a wasteful number, since it uses less digits than its factorization.

669751 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6040.

The product of its digits is 11340, while the sum is 34.

The square root of 669751 is about 818.3831620946. The cubic root of 669751 is about 87.4925599116.

The spelling of 669751 in words is "six hundred sixty-nine thousand, seven hundred fifty-one".