66678945 has 16 divisors (see below), whose sum is σ = 106927872. Its totient is φ = 35481600.

The previous prime is 66678901. The next prime is 66678949. The reversal of 66678945 is 54987666.

It is not a de Polignac number, because 66678945 - 2⁶ = 66678881 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66678949) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2145 + ... + 11745.

It is an arithmetic number, because the mean of its divisors is an integer number (6682992).

Almost surely, 2^66678945 is an apocalyptic number.

It is an amenable number.

66678945 is a deficient number, since it is larger than the sum of its proper divisors (40248927).

66678945 is a wasteful number, since it uses less digits than its factorization.

66678945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10072.

The product of its digits is 2177280, while the sum is 51.

The square root of 66678945 is about 8165.7176659495. The cubic root of 66678945 is about 405.5050246113.

The spelling of 66678945 in words is "sixty-six million, six hundred seventy-eight thousand, nine hundred forty-five".