66513257145 has 12 divisors (see below), whose sum is σ = 115289645796. Its totient is φ = 35473737120.

The previous prime is 66513257113. The next prime is 66513257191. The reversal of 66513257145 is 54175231566.

66513257145 is a `hidden beast` number, since 6 + 6 + 5 + 1 + 32 + 571 + 45 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 15276218409 + 51237038736 = 123597^2 + 226356^2 .

It is not a de Polignac number, because 66513257145 - 2⁵ = 66513257113 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45), and also a Moran number because the ratio is a prime number: 1478072381 = 66513257145 / (6 + 6 + 5 + 1 + 3 + 2 + 5 + 7 + 1 + 4 + 5).

It is a self number, because there is not a number n which added to its sum of digits gives 66513257145.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 739036146 + ... + 739036235.

It is an arithmetic number, because the mean of its divisors is an integer number (9607470483).

Almost surely, 2^66513257145 is an apocalyptic number.

It is an amenable number.

66513257145 is a deficient number, since it is larger than the sum of its proper divisors (48776388651).

66513257145 is a wasteful number, since it uses less digits than its factorization.

66513257145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1478072392 (or 1478072389 counting only the distinct ones).

The product of its digits is 756000, while the sum is 45.

The spelling of 66513257145 in words is "sixty-six billion, five hundred thirteen million, two hundred fifty-seven thousand, one hundred forty-five".