65640017 has 4 divisors (see below), whose sum is σ = 65656500. Its totient is φ = 65623536.

The previous prime is 65639993. The next prime is 65640019. The reversal of 65640017 is 71004656.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 43020481 + 22619536 = 6559^2 + 4756^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-65640017 is a prime.

It is a super-2 number, since 2×65640017² = 8617223663520578, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65640019) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1859 + ... + 11607.

It is an arithmetic number, because the mean of its divisors is an integer number (16414125).

Almost surely, 2^65640017 is an apocalyptic number.

It is an amenable number.

65640017 is a deficient number, since it is larger than the sum of its proper divisors (16483).

65640017 is an equidigital number, since it uses as much as digits as its factorization.

65640017 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16482.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 65640017 is about 8101.8526893545. The cubic root of 65640017 is about 403.3879259634.

The spelling of 65640017 in words is "sixty-five million, six hundred forty thousand, seventeen".