66105656251 has 8 divisors (see below), whose sum is σ = 67438151424. Its totient is φ = 64784312040.

The previous prime is 66105656237. The next prime is 66105656257. The reversal of 66105656251 is 15265650166.

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 66105656251 - 2¹⁷ = 66105525179 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66105656198 and 66105656207.

It is not an unprimeable number, because it can be changed into a prime (66105656257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2775765 + ... + 2799478.

It is an arithmetic number, because the mean of its divisors is an integer number (8429768928).

Almost surely, 2^66105656251 is an apocalyptic number.

66105656251 is a deficient number, since it is larger than the sum of its proper divisors (1332495173).

66105656251 is a wasteful number, since it uses less digits than its factorization.

66105656251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5575481.

The product of its (nonzero) digits is 324000, while the sum is 43.

The spelling of 66105656251 in words is "sixty-six billion, one hundred five million, six hundred fifty-six thousand, two hundred fifty-one".