669919 has 8 divisors (see below), whose sum is σ = 716688. Its totient is φ = 624000.

The previous prime is 669913. The next prime is 669923. The reversal of 669919 is 919966.

669919 = T₂ + T₃ + ... + T₁₅₈.

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

It is a cyclic number.

It is not a de Polignac number, because 669919 - 2⁵ = 669887 is a prime.

It is a super-2 number, since 2×669919² = 897582933122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669913) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2544 + ... + 2794.

It is an arithmetic number, because the mean of its divisors is an integer number (89586).

2⁶⁶⁹⁹¹⁹ is an apocalyptic number.

669919 is a deficient number, since it is larger than the sum of its proper divisors (46769).

669919 is a wasteful number, since it uses less digits than its factorization.

669919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425.

The product of its digits is 26244, while the sum is 40.

The square root of 669919 is about 818.4857970668. The cubic root of 669919 is about 87.4998748298.

Subtracting 669919 from its reverse (919966), we obtain a cube (250047 = 63³).

The spelling of 669919 in words is "six hundred sixty-nine thousand, nine hundred nineteen".