66515641028 has 24 divisors (see below), whose sum is σ = 125517325920. Its totient is φ = 30738934080.

The previous prime is 66515641021. The next prime is 66515641033. The reversal of 66515641028 is 82014651566.

It is a self number, because there is not a number n which added to its sum of digits gives 66515641028.

It is not an unprimeable number, because it can be changed into a prime (66515641021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10670126 + ... + 10676357.

It is an arithmetic number, because the mean of its divisors is an integer number (5229888580).

Almost surely, 2^66515641028 is an apocalyptic number.

It is an amenable number.

66515641028 is a deficient number, since it is larger than the sum of its proper divisors (59001684892).

66515641028 is a wasteful number, since it uses less digits than its factorization.

66515641028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21346547 (or 21346545 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 44.

The spelling of 66515641028 in words is "sixty-six billion, five hundred fifteen million, six hundred forty-one thousand, twenty-eight".