66615407 has 8 divisors (see below), whose sum is σ = 69787200. Its totient is φ = 63501984.

The previous prime is 66615397. The next prime is 66615427. The reversal of 66615407 is 70451666.

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 66615407 - 2⁴ = 66615391 is a prime.

It is a super-2 number, since 2×66615407² = 8875224899551298, 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 (66615427) by changing a digit.

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, 12248 + ... + 16829.

It is an arithmetic number, because the mean of its divisors is an integer number (8723400).

Almost surely, 2^66615407 is an apocalyptic number.

66615407 is a deficient number, since it is larger than the sum of its proper divisors (3171793).

66615407 is a wasteful number, since it uses less digits than its factorization.

66615407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29185.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 66615407 is about 8161.8262049617. The cubic root of 66615407 is about 405.3761825090.

The spelling of 66615407 in words is "sixty-six million, six hundred fifteen thousand, four hundred seven".