66670646751 has 64 divisors (see below), whose sum is σ = 104702400000. Its totient is φ = 41856756480.

The previous prime is 66670646741. The next prime is 66670646761. The reversal of 66670646751 is 15764607666.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66670646741) and next prime (66670646761).

It is not a de Polignac number, because 66670646751 - 2¹⁵ = 66670613983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66670646711) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 44476000 + ... + 44477498.

It is an arithmetic number, because the mean of its divisors is an integer number (1635975000).

Almost surely, 2^66670646751 is an apocalyptic number.

66670646751 is a deficient number, since it is larger than the sum of its proper divisors (38031753249).

66670646751 is a wasteful number, since it uses less digits than its factorization.

66670646751 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2901 (or 2895 counting only the distinct ones).

The product of its (nonzero) digits is 7620480, while the sum is 54.

The spelling of 66670646751 in words is "sixty-six billion, six hundred seventy million, six hundred forty-six thousand, seven hundred fifty-one".