66566571650 has 48 divisors (see below), whose sum is σ = 126277245864. Its totient is φ = 26097876480.

The previous prime is 66566571613. The next prime is 66566571677. The reversal of 66566571650 is 5617566566.

It can be written as a sum of positive squares in 12 ways, for example, as 31439190721 + 35127380929 = 177311^2 + 187423^2 .

It is a super-2 number, since 2×66566571650² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (53).

It is a junction number, because it is equal to n+sod(n) for n = 66566571592 and 66566571601.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2725292 + ... + 2749608.

Almost surely, 2^66566571650 is an apocalyptic number.

66566571650 is a deficient number, since it is larger than the sum of its proper divisors (59710674214).

66566571650 is a wasteful number, since it uses less digits than its factorization.

66566571650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25415 (or 25410 counting only the distinct ones).

The product of its (nonzero) digits is 6804000, while the sum is 53.

The spelling of 66566571650 in words is "sixty-six billion, five hundred sixty-six million, five hundred seventy-one thousand, six hundred fifty".