66535215420 has 48 divisors (see below), whose sum is σ = 186624966528. Its totient is φ = 17711641920.

The previous prime is 66535215367. The next prime is 66535215421. The reversal of 66535215420 is 2451253566.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66535215421) by changing a digit.

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, 936774 + ... + 1005293.

It is an arithmetic number, because the mean of its divisors is an integer number (3888020136).

Almost surely, 2^66535215420 is an apocalyptic number.

66535215420 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66535215420 is an abundant number, since it is smaller than the sum of its proper divisors (120089751108).

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

66535215420 is a wasteful number, since it uses less digits than its factorization.

66535215420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1942650 (or 1942648 counting only the distinct ones).

The product of its (nonzero) digits is 216000, while the sum is 39.

Adding to 66535215420 its reverse (2451253566), we get a palindrome (68986468986).

The spelling of 66535215420 in words is "sixty-six billion, five hundred thirty-five million, two hundred fifteen thousand, four hundred twenty".