66855469 has 4 divisors (see below), whose sum is σ = 69160860. Its totient is φ = 64550080.

The previous prime is 66855463. The next prime is 66855473. The reversal of 66855469 is 96455866.

It is a happy number.

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 31214569 + 35640900 = 5587^2 + 5970^2 .

It is a cyclic number.

It is not a de Polignac number, because 66855469 - 2¹¹ = 66853421 is a prime.

It is a super-2 number, since 2×66855469² = 8939307470419922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66855463) 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, 1152652 + ... + 1152709.

It is an arithmetic number, because the mean of its divisors is an integer number (17290215).

Almost surely, 2^66855469 is an apocalyptic number.

It is an amenable number.

66855469 is a deficient number, since it is larger than the sum of its proper divisors (2305391).

66855469 is a wasteful number, since it uses less digits than its factorization.

66855469 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2305390.

The product of its digits is 1555200, while the sum is 49.

The square root of 66855469 is about 8176.5193695117. The cubic root of 66855469 is about 405.8625502350.

The spelling of 66855469 in words is "sixty-six million, eight hundred fifty-five thousand, four hundred sixty-nine".