669920509440 has 1280 divisors, whose sum is σ = 2970909849600. Its totient is φ = 139314069504.

The previous prime is 669920509421. The next prime is 669920509469. The reversal of 669920509440 is 44905029966.

It is a happy number.

669920509440 is a `hidden beast` number, since 6 + 6 + 9 + 92 + 0 + 509 + 4 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (1280).

It is a super-2 number, since 2×669920509440² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 459163431 + ... + 459164889.

It is an arithmetic number, because the mean of its divisors is an integer number (2321023320).

Almost surely, 2^669920509440 is an apocalyptic number.

669920509440 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 669920509440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1485454924800).

669920509440 is an abundant number, since it is smaller than the sum of its proper divisors (2300989340160).

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

669920509440 is a wasteful number, since it uses less digits than its factorization.

669920509440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1584 (or 1562 counting only the distinct ones).

The product of its (nonzero) digits is 4199040, while the sum is 54.

The spelling of 669920509440 in words is "six hundred sixty-nine billion, nine hundred twenty million, five hundred nine thousand, four hundred forty".