66507865 has 8 divisors (see below), whose sum is σ = 82384128. Its totient is φ = 51489840.

The previous prime is 66507851. The next prime is 66507871. The reversal of 66507865 is 56870566.

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

It is not a de Polignac number, because 66507865 - 2⁷ = 66507737 is a prime.

It is a super-2 number, since 2×66507865² = 8846592213716450, which contains 22 as substring.

It is a Duffinian number.

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, 214387 + ... + 214696.

It is an arithmetic number, because the mean of its divisors is an integer number (10298016).

Almost surely, 2^66507865 is an apocalyptic number.

It is an amenable number.

66507865 is a deficient number, since it is larger than the sum of its proper divisors (15876263).

66507865 is a wasteful number, since it uses less digits than its factorization.

66507865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429119.

The product of its (nonzero) digits is 302400, while the sum is 43.

The square root of 66507865 is about 8155.2354349829. The cubic root of 66507865 is about 405.1579224601.

The spelling of 66507865 in words is "sixty-six million, five hundred seven thousand, eight hundred sixty-five".