66405505501 has 8 divisors (see below), whose sum is σ = 67257319680. Its totient is φ = 65553972432.

The previous prime is 66405505403. The next prime is 66405505613. The reversal of 66405505501 is 10550550466.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66405505501 - 2¹¹ = 66405503453 is a prime.

It is a super-2 number, since 2×66405505501² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66405506501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 427671 + ... + 561883.

It is an arithmetic number, because the mean of its divisors is an integer number (8407164960).

Almost surely, 2^66405505501 is an apocalyptic number.

It is an amenable number.

66405505501 is a deficient number, since it is larger than the sum of its proper divisors (851814179).

66405505501 is a wasteful number, since it uses less digits than its factorization.

66405505501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140555.

The product of its (nonzero) digits is 90000, while the sum is 37.

The spelling of 66405505501 in words is "sixty-six billion, four hundred five million, five hundred five thousand, five hundred one".