66789975 has 24 divisors (see below), whose sum is σ = 126202240. Its totient is φ = 30532320.

The previous prime is 66789971. The next prime is 66789979. The reversal of 66789975 is 57998766.

It is an interprime number because it is at equal distance from previous prime (66789971) and next prime (66789979).

It is not a de Polignac number, because 66789975 - 2² = 66789971 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66789971) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 63085 + ... + 64134.

Almost surely, 2^66789975 is an apocalyptic number.

66789975 is a deficient number, since it is larger than the sum of its proper divisors (59412265).

66789975 is a wasteful number, since it uses less digits than its factorization.

66789975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127239 (or 127234 counting only the distinct ones).

The product of its digits is 5715360, while the sum is 57.

The square root of 66789975 is about 8172.5133832867. The cubic root of 66789975 is about 405.7299744609.

It can be divided in two parts, 6678 and 9975, that added together give a triangular number (16653 = T₁₈₂).

The spelling of 66789975 in words is "sixty-six million, seven hundred eighty-nine thousand, nine hundred seventy-five".