66518365870 has 32 divisors (see below), whose sum is σ = 132831757440. Its totient is φ = 23778519840.

The previous prime is 66518365861. The next prime is 66518365873. The reversal of 66518365870 is 7856381566.

It is a Harshad number since it is a multiple of its sum of digits (55).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66518365873) 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, 5118192 + ... + 5131171.

It is an arithmetic number, because the mean of its divisors is an integer number (4150992420).

Almost surely, 2^66518365870 is an apocalyptic number.

66518365870 is a deficient number, since it is larger than the sum of its proper divisors (66313391570).

66518365870 is a wasteful number, since it uses less digits than its factorization.

66518365870 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10249440.

The product of its (nonzero) digits is 7257600, while the sum is 55.

The spelling of 66518365870 in words is "sixty-six billion, five hundred eighteen million, three hundred sixty-five thousand, eight hundred seventy".