66565501 has 4 divisors (see below), whose sum is σ = 67211872. Its totient is φ = 65919132.

The previous prime is 66565483. The next prime is 66565529. The reversal of 66565501 is 10556566.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66565501 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 (66565001) 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, 323031 + ... + 323236.

It is an arithmetic number, because the mean of its divisors is an integer number (16802968).

Almost surely, 2^66565501 is an apocalyptic number.

It is an amenable number.

66565501 is a deficient number, since it is larger than the sum of its proper divisors (646371).

66565501 is a wasteful number, since it uses less digits than its factorization.

66565501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646370.

The product of its (nonzero) digits is 27000, while the sum is 34.

The square root of 66565501 is about 8158.7683506765. The cubic root of 66565501 is about 405.2749258637.

It can be divided in two parts, 665 and 65501, that added together give a palindrome (66166).

The spelling of 66565501 in words is "sixty-six million, five hundred sixty-five thousand, five hundred one".