66605399040 has 352 divisors, whose sum is σ = 220439301120. Its totient is φ = 17151492096.

The previous prime is 66605399027. The next prime is 66605399051. The reversal of 66605399040 is 4099350666.

It is a happy number.

66605399040 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 92635801 + ... + 92636519.

Almost surely, 2^66605399040 is an apocalyptic number.

66605399040 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 66605399040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110219650560).

66605399040 is an abundant number, since it is smaller than the sum of its proper divisors (153833902080).

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

66605399040 is a wasteful number, since it uses less digits than its factorization.

66605399040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 947 (or 929 counting only the distinct ones).

The product of its (nonzero) digits is 1049760, while the sum is 48.

The spelling of 66605399040 in words is "sixty-six billion, six hundred five million, three hundred ninety-nine thousand, forty".