66145540 has 12 divisors (see below), whose sum is σ = 138905676. Its totient is φ = 26458208.

The previous prime is 66145531. The next prime is 66145543. The reversal of 66145540 is 4554166.

It can be written as a sum of positive squares in 2 ways, for example, as 47775744 + 18369796 = 6912^2 + 4286^2 .

It is not an unprimeable number, because it can be changed into a prime (66145543) 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, 1653619 + ... + 1653658.

It is an arithmetic number, because the mean of its divisors is an integer number (11575473).

Almost surely, 2^66145540 is an apocalyptic number.

It is an amenable number.

66145540 is an abundant number, since it is smaller than the sum of its proper divisors (72760136).

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

66145540 is a wasteful number, since it uses less digits than its factorization.

66145540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3307286 (or 3307284 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 66145540 is about 8132.9908397834. The cubic root of 66145540 is about 404.4208355332.

The spelling of 66145540 in words is "sixty-six million, one hundred forty-five thousand, five hundred forty".