66156363125561 has 8 divisors (see below), whose sum is σ = 66252569965824. Its totient is φ = 66060213710400.

The previous prime is 66156363125533. The next prime is 66156363125563. The reversal of 66156363125561 is 16552136365166.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66156363125561 - 2²⁶ = 66156296016697 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66156363125497 and 66156363125506.

It is not an unprimeable number, because it can be changed into a prime (66156363125563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12050240 + ... + 16658961.

It is an arithmetic number, because the mean of its divisors is an integer number (8281571245728).

Almost surely, 2^{66156363125561} is an apocalyptic number.

It is an amenable number.

66156363125561 is a deficient number, since it is larger than the sum of its proper divisors (96206840263).

66156363125561 is a wasteful number, since it uses less digits than its factorization.

66156363125561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28712551.

The product of its digits is 17496000, while the sum is 56.

The spelling of 66156363125561 in words is "sixty-six trillion, one hundred fifty-six billion, three hundred sixty-three million, one hundred twenty-five thousand, five hundred sixty-one".