66503136840 has 128 divisors (see below), whose sum is σ = 228219552000. Its totient is φ = 15186797568.

The previous prime is 66503136797. The next prime is 66503136841. The reversal of 66503136840 is 4863130566.

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

It is a junction number, because it is equal to n+sod(n) for n = 66503136792 and 66503136801.

It is not an unprimeable number, because it can be changed into a prime (66503136841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 895866 + ... + 967254.

It is an arithmetic number, because the mean of its divisors is an integer number (1782965250).

Almost surely, 2^66503136840 is an apocalyptic number.

66503136840 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 66503136840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114109776000).

66503136840 is an abundant number, since it is smaller than the sum of its proper divisors (161716415160).

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

66503136840 is a wasteful number, since it uses less digits than its factorization.

66503136840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72519 (or 72515 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 42.

The spelling of 66503136840 in words is "sixty-six billion, five hundred three million, one hundred thirty-six thousand, eight hundred forty".