66945251 has 8 divisors (see below), whose sum is σ = 68889744. Its totient is φ = 65015680.

The previous prime is 66945239. The next prime is 66945257. The reversal of 66945251 is 15254966.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66945251 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66945257) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5711 + ... + 12903.

It is an arithmetic number, because the mean of its divisors is an integer number (8611218).

Almost surely, 2^66945251 is an apocalyptic number.

66945251 is a deficient number, since it is larger than the sum of its proper divisors (1944493).

66945251 is a wasteful number, since it uses less digits than its factorization.

66945251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7461.

The product of its digits is 64800, while the sum is 38.

The square root of 66945251 is about 8182.0077609350. The cubic root of 66945251 is about 406.0441501972.

The spelling of 66945251 in words is "sixty-six million, nine hundred forty-five thousand, two hundred fifty-one".