66609329400 has 480 divisors, whose sum is σ = 246030190560. Its totient is φ = 16664693760.

The previous prime is 66609329351. The next prime is 66609329473. The reversal of 66609329400 is 492390666.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 19746114 + ... + 19749486.

It is an arithmetic number, because the mean of its divisors is an integer number (512562897).

Almost surely, 2^66609329400 is an apocalyptic number.

66609329400 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 66609329400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (123015095280).

66609329400 is an abundant number, since it is smaller than the sum of its proper divisors (179420861160).

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

66609329400 is a wasteful number, since it uses less digits than its factorization.

66609329400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3477 (or 3459 counting only the distinct ones).

The product of its (nonzero) digits is 419904, while the sum is 45.

The spelling of 66609329400 in words is "sixty-six billion, six hundred nine million, three hundred twenty-nine thousand, four hundred".