66042665 has 12 divisors (see below), whose sum is σ = 85817484. Its totient is φ = 48769344.

The previous prime is 66042659. The next prime is 66042703. The reversal of 66042665 is 56624066.

It can be written as a sum of positive squares in 6 ways, for example, as 34727449 + 31315216 = 5893^2 + 5596^2 .

It is not a de Polignac number, because 66042665 - 2⁶ = 66042601 is a prime.

It is a Duffinian number.

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, 38234 + ... + 39923.

It is an arithmetic number, because the mean of its divisors is an integer number (7151457).

Almost surely, 2^66042665 is an apocalyptic number.

66042665 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

66042665 is a deficient number, since it is larger than the sum of its proper divisors (19774819).

66042665 is a wasteful number, since it uses less digits than its factorization.

66042665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78188 (or 78175 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 35.

The square root of 66042665 is about 8126.6638296413. The cubic root of 66042665 is about 404.2110638632.

The spelling of 66042665 in words is "sixty-six million, forty-two thousand, six hundred sixty-five".