669486420 has 72 divisors (see below), whose sum is σ = 2042094600. Its totient is φ = 177534720.

The previous prime is 669486403. The next prime is 669486427. The reversal of 669486420 is 24684966.

669486420 is a `hidden beast` number, since 66 + 94 + 86 + 420 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 60186564 + 609299856 = 7758^2 + 24684^2 .

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (669486427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22306 + ... + 42854.

It is an arithmetic number, because the mean of its divisors is an integer number (28362425).

Almost surely, 2^669486420 is an apocalyptic number.

669486420 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 669486420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1021047300).

669486420 is an abundant number, since it is smaller than the sum of its proper divisors (1372608180).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

669486420 is a wasteful number, since it uses less digits than its factorization.

669486420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20745 (or 20740 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 45.

The square root of 669486420 is about 25874.4356460194. The cubic root of 669486420 is about 874.8103730573.

The spelling of 669486420 in words is "six hundred sixty-nine million, four hundred eighty-six thousand, four hundred twenty".