66678577 has 4 divisors (see below), whose sum is σ = 76204096. Its totient is φ = 57153060.

The previous prime is 66678553. The next prime is 66678583. The reversal of 66678577 is 77587666.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66678577 - 2¹⁹ = 66154289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66678517) 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 3 ways as a sum of consecutive naturals, for example, 4762749 + ... + 4762762.

It is an arithmetic number, because the mean of its divisors is an integer number (19051024).

Almost surely, 2^66678577 is an apocalyptic number.

It is an amenable number.

66678577 is a deficient number, since it is larger than the sum of its proper divisors (9525519).

66678577 is an equidigital number, since it uses as much as digits as its factorization.

66678577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9525518.

The product of its digits is 2963520, while the sum is 52.

The square root of 66678577 is about 8165.6951326877. The cubic root of 66678577 is about 405.5042786181.

The spelling of 66678577 in words is "sixty-six million, six hundred seventy-eight thousand, five hundred seventy-seven".