66515661511 has 8 divisors (see below), whose sum is σ = 71798457024. Its totient is φ = 61256609760.

The previous prime is 66515661467. The next prime is 66515661517. The reversal of 66515661511 is 11516651566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66515661511 - 2⁷ = 66515661383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66515661517) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5930116 + ... + 5941321.

It is an arithmetic number, because the mean of its divisors is an integer number (8974807128).

Almost surely, 2^66515661511 is an apocalyptic number.

66515661511 is a deficient number, since it is larger than the sum of its proper divisors (5282795513).

66515661511 is a wasteful number, since it uses less digits than its factorization.

66515661511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11871881.

The product of its digits is 162000, while the sum is 43.

The spelling of 66515661511 in words is "sixty-six billion, five hundred fifteen million, six hundred sixty-one thousand, five hundred eleven".