66057050261981 has 8 divisors (see below), whose sum is σ = 66417851785728. Its totient is φ = 65696404500000.

The previous prime is 66057050261959. The next prime is 66057050261999. The reversal of 66057050261981 is 18916205075066.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66057050261981 is a prime.

It is a super-2 number, since 2×66057050261981² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66057050261281) 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, 38089895 + ... + 39786356.

It is an arithmetic number, because the mean of its divisors is an integer number (8302231473216).

Almost surely, 2^{66057050261981} is an apocalyptic number.

It is an amenable number.

66057050261981 is a deficient number, since it is larger than the sum of its proper divisors (360801523747).

66057050261981 is a wasteful number, since it uses less digits than its factorization.

66057050261981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77880883.

The product of its (nonzero) digits is 5443200, while the sum is 56.

The spelling of 66057050261981 in words is "sixty-six trillion, fifty-seven billion, fifty million, two hundred sixty-one thousand, nine hundred eighty-one".