66511027640 has 16 divisors (see below), whose sum is σ = 149649812280. Its totient is φ = 26604411040.

The previous prime is 66511027637. The next prime is 66511027663. The reversal of 66511027640 is 4672011566.

It is a junction number, because it is equal to n+sod(n) for n = 66511027594 and 66511027603.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 831387806 + ... + 831387885.

Almost surely, 2^66511027640 is an apocalyptic number.

It is an amenable number.

66511027640 is an abundant number, since it is smaller than the sum of its proper divisors (83138784640).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66511027640 is a wasteful number, since it uses less digits than its factorization.

66511027640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1662775702 (or 1662775698 counting only the distinct ones).

The product of its (nonzero) digits is 60480, while the sum is 38.

The spelling of 66511027640 in words is "sixty-six billion, five hundred eleven million, twenty-seven thousand, six hundred forty".