66566515515 has 8 divisors (see below), whose sum is σ = 106506424848. Its totient is φ = 35502141600.

The previous prime is 66566515487. The next prime is 66566515541. The reversal of 66566515515 is 51551566566.

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

It is not a de Polignac number, because 66566515515 - 2⁷ = 66566515387 is a prime.

It is a super-2 number, since 2×66566515515² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2218883836 + ... + 2218883865.

It is an arithmetic number, because the mean of its divisors is an integer number (13313303106).

Almost surely, 2^66566515515 is an apocalyptic number.

66566515515 is a deficient number, since it is larger than the sum of its proper divisors (39939909333).

66566515515 is a wasteful number, since it uses less digits than its factorization.

66566515515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4437767709.

The product of its digits is 4050000, while the sum is 51.

The spelling of 66566515515 in words is "sixty-six billion, five hundred sixty-six million, five hundred fifteen thousand, five hundred fifteen".