66685251 has 8 divisors (see below), whose sum is σ = 89313280. Its totient is φ = 44257032.

The previous prime is 66685249. The next prime is 66685253. The reversal of 66685251 is 15258666.

It is an interprime number because it is at equal distance from previous prime (66685249) and next prime (66685253).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66685251 - 2¹ = 66685249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66685253) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49171 + ... + 50508.

It is an arithmetic number, because the mean of its divisors is an integer number (11164160).

Almost surely, 2^66685251 is an apocalyptic number.

66685251 is a deficient number, since it is larger than the sum of its proper divisors (22628029).

66685251 is a wasteful number, since it uses less digits than its factorization.

66685251 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99905.

The product of its digits is 86400, while the sum is 39.

The square root of 66685251 is about 8166.1037833229. The cubic root of 66685251 is about 405.5178074274.

The spelling of 66685251 in words is "sixty-six million, six hundred eighty-five thousand, two hundred fifty-one".