66212657551161 has 192 divisors, whose sum is σ = 114641830517760. Its totient is φ = 37768032000000.

The previous prime is 66212657551153. The next prime is 66212657551193. The reversal of 66212657551161 is 16115575621266.

It is a happy number.

66212657551161 is a `hidden beast` number, since 6 + 6 + 2 + 1 + 2 + 6 + 575 + 5 + 1 + 1 + 61 = 666.

It is not a de Polignac number, because 66212657551161 - 2³ = 66212657551153 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66212657551098 and 66212657551107.

It is not an unprimeable number, because it can be changed into a prime (66212657551111) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 5111755861 + ... + 5111768813.

It is an arithmetic number, because the mean of its divisors is an integer number (597092867280).

Almost surely, 2^{66212657551161} is an apocalyptic number.

It is an amenable number.

66212657551161 is a deficient number, since it is larger than the sum of its proper divisors (48429172966599).

66212657551161 is a wasteful number, since it uses less digits than its factorization.

66212657551161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13650 (or 13638 counting only the distinct ones).

The product of its digits is 4536000, while the sum is 54.

The spelling of 66212657551161 in words is "sixty-six trillion, two hundred twelve billion, six hundred fifty-seven million, five hundred fifty-one thousand, one hundred sixty-one".