66522565 has 4 divisors (see below), whose sum is σ = 79827084. Its totient is φ = 53218048.

The previous prime is 66522557. The next prime is 66522569. The reversal of 66522565 is 56522566.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 47320641 + 19201924 = 6879^2 + 4382^2 .

It is a cyclic number.

It is not a de Polignac number, because 66522565 - 2³ = 66522557 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 (66522569) 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, 6652252 + ... + 6652261.

It is an arithmetic number, because the mean of its divisors is an integer number (19956771).

Almost surely, 2^66522565 is an apocalyptic number.

It is an amenable number.

66522565 is a deficient number, since it is larger than the sum of its proper divisors (13304519).

66522565 is a wasteful number, since it uses less digits than its factorization.

66522565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13304518.

The product of its digits is 108000, while the sum is 37.

The square root of 66522565 is about 8156.1366467219. The cubic root of 66522565 is about 405.1877704724.

Subtracting from 66522565 its reverse (56522566), we obtain a palindrome (9999999).

The spelling of 66522565 in words is "sixty-six million, five hundred twenty-two thousand, five hundred sixty-five".