66535985040 has 320 divisors, whose sum is σ = 240704593920. Its totient is φ = 14889277440.

The previous prime is 66535985003. The next prime is 66535985053. The reversal of 66535985040 is 4058953566.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 26860282 + ... + 26862758.

It is an arithmetic number, because the mean of its divisors is an integer number (752201856).

Almost surely, 2^66535985040 is an apocalyptic number.

66535985040 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 66535985040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120352296960).

66535985040 is an abundant number, since it is smaller than the sum of its proper divisors (174168608880).

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

66535985040 is a wasteful number, since it uses less digits than its factorization.

66535985040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2830 (or 2824 counting only the distinct ones).

The product of its (nonzero) digits is 3888000, while the sum is 51.

The spelling of 66535985040 in words is "sixty-six billion, five hundred thirty-five million, nine hundred eighty-five thousand, forty".