669421440 has 384 divisors, whose sum is σ = 2505185280. Its totient is φ = 164229120.

The previous prime is 669421439. The next prime is 669421457. The reversal of 669421440 is 44124966.

669421440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 669421395 and 669421404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4106799 + ... + 4106961.

It is an arithmetic number, because the mean of its divisors is an integer number (6523920).

Almost surely, 2^669421440 is an apocalyptic number.

669421440 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 669421440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1252592640).

669421440 is an abundant number, since it is smaller than the sum of its proper divisors (1835763840).

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

669421440 is a wasteful number, since it uses less digits than its factorization.

669421440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242 (or 227 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 669421440 is about 25873.1799359878. The cubic root of 669421440 is about 874.7820692633.

The spelling of 669421440 in words is "six hundred sixty-nine million, four hundred twenty-one thousand, four hundred forty".