66681415 has 8 divisors (see below), whose sum is σ = 81212400. Its totient is φ = 52548672.

The previous prime is 66681409. The next prime is 66681467. The reversal of 66681415 is 51418666.

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

It is a cyclic number.

It is not a de Polignac number, because 66681415 - 2⁵ = 66681383 is a prime.

It is a super-2 number, since 2×66681415² = 8892822212804450, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 99190 + ... + 99859.

It is an arithmetic number, because the mean of its divisors is an integer number (10151550).

Almost surely, 2^66681415 is an apocalyptic number.

66681415 is a deficient number, since it is larger than the sum of its proper divisors (14530985).

66681415 is a wasteful number, since it uses less digits than its factorization.

66681415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199121.

The product of its digits is 34560, while the sum is 37.

The square root of 66681415 is about 8165.8689066137. The cubic root of 66681415 is about 405.5100316144.

The spelling of 66681415 in words is "sixty-six million, six hundred eighty-one thousand, four hundred fifteen".