66506516 has 12 divisors (see below), whose sum is σ = 123232788. Its totient is φ = 31297152.

The previous prime is 66506507. The next prime is 66506519. The reversal of 66506516 is 61560566.

It can be written as a sum of positive squares in 2 ways, for example, as 23078416 + 43428100 = 4804^2 + 6590^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66506519) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 488951 + ... + 489086.

It is an arithmetic number, because the mean of its divisors is an integer number (10269399).

Almost surely, 2^66506516 is an apocalyptic number.

It is an amenable number.

66506516 is a deficient number, since it is larger than the sum of its proper divisors (56726272).

66506516 is a wasteful number, since it uses less digits than its factorization.

66506516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 978058 (or 978056 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 35.

The square root of 66506516 is about 8155.1527269574. The cubic root of 66506516 is about 405.1551831263.

The spelling of 66506516 in words is "sixty-six million, five hundred six thousand, five hundred sixteen".