66989625 has 16 divisors (see below), whose sum is σ = 111471360. Its totient is φ = 35727600.

The previous prime is 66989591. The next prime is 66989627. The reversal of 66989625 is 52698966.

It is not a de Polignac number, because 66989625 - 2⁶ = 66989561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66989627) 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 15 ways as a sum of consecutive naturals, for example, 88945 + ... + 89694.

It is an arithmetic number, because the mean of its divisors is an integer number (6966960).

Almost surely, 2^66989625 is an apocalyptic number.

It is an amenable number.

66989625 is a deficient number, since it is larger than the sum of its proper divisors (44481735).

66989625 is a wasteful number, since it uses less digits than its factorization.

66989625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178657 (or 178647 counting only the distinct ones).

The product of its digits is 1399680, while the sum is 51.

The square root of 66989625 is about 8184.7189933436. The cubic root of 66989625 is about 406.1338445039.

The spelling of 66989625 in words is "sixty-six million, nine hundred eighty-nine thousand, six hundred twenty-five".