669438883440 has 80 divisors (see below), whose sum is σ = 2305845050400. Its totient is φ = 178517035008.

The previous prime is 669438883411. The next prime is 669438883517. The reversal of 669438883440 is 44388834966.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×669438883440² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

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 15 ways as a sum of consecutive naturals, for example, 154960545 + ... + 154964864.

It is an arithmetic number, because the mean of its divisors is an integer number (28823063130).

Almost surely, 2^669438883440 is an apocalyptic number.

669438883440 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

669438883440 is an abundant number, since it is smaller than the sum of its proper divisors (1636406166960).

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

669438883440 is a wasteful number, since it uses less digits than its factorization.

669438883440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309925431 (or 309925419 counting only the distinct ones).

The product of its (nonzero) digits is 95551488, while the sum is 63.

The spelling of 669438883440 in words is "six hundred sixty-nine billion, four hundred thirty-eight million, eight hundred eighty-three thousand, four hundred forty".