66501312516 has 36 divisors (see below), whose sum is σ = 168172074252. Its totient is φ = 22157671104.

The previous prime is 66501312491. The next prime is 66501312629. The reversal of 66501312516 is 61521310566.

66501312516 is a `hidden beast` number, since 6 + 6 + 5 + 0 + 131 + 2 + 516 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 31042916100 + 35458396416 = 176190^2 + 188304^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 307015 + ... + 476718.

It is an arithmetic number, because the mean of its divisors is an integer number (4671446507).

Almost surely, 2^66501312516 is an apocalyptic number.

It is an amenable number.

66501312516 is an abundant number, since it is smaller than the sum of its proper divisors (101670761736).

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

66501312516 is a wasteful number, since it uses less digits than its factorization.

66501312516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 786100 (or 786095 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The spelling of 66501312516 in words is "sixty-six billion, five hundred one million, three hundred twelve thousand, five hundred sixteen".