66929681 has 8 divisors (see below), whose sum is σ = 82375104. Its totient is φ = 52955280.

The previous prime is 66929591. The next prime is 66929743. The reversal of 66929681 is 18692966.

66929681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 66929681 - 2¹⁸ = 66667537 is a prime.

It is a super-2 number, since 2×66929681² = 8959164397523522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66929281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 367655 + ... + 367836.

It is an arithmetic number, because the mean of its divisors is an integer number (10296888).

Almost surely, 2^66929681 is an apocalyptic number.

It is an amenable number.

66929681 is a deficient number, since it is larger than the sum of its proper divisors (15445423).

66929681 is a wasteful number, since it uses less digits than its factorization.

66929681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 735511.

The product of its digits is 279936, while the sum is 47.

The square root of 66929681 is about 8181.0562276518. The cubic root of 66929681 is about 406.0126687627.

The spelling of 66929681 in words is "sixty-six million, nine hundred twenty-nine thousand, six hundred eighty-one".