66442120550610 has 320 divisors, whose sum is σ = 202134587166720. Its totient is φ = 13923345985920.

The previous prime is 66442120550599. The next prime is 66442120550623. The reversal of 66442120550610 is 1605502124466.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 41642629 + ... + 43208711.

It is an arithmetic number, because the mean of its divisors is an integer number (631670584896).

Almost surely, 2^{66442120550610} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66442120550610, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101067293583360).

66442120550610 is an abundant number, since it is smaller than the sum of its proper divisors (135692466616110).

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

66442120550610 is a wasteful number, since it uses less digits than its factorization.

66442120550610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1566171 (or 1566150 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 42.

The spelling of 66442120550610 in words is "sixty-six trillion, four hundred forty-two billion, one hundred twenty million, five hundred fifty thousand, six hundred ten".