81572189141066 has 32 divisors (see below), whose sum is σ = 134265092140368. Its totient is φ = 36936039329280.

The previous prime is 81572189141041. The next prime is 81572189141089. The reversal of 81572189141066 is 66014198127518.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 11975233275625 + 69596955865441 = 3460525^2 + 8342479^2 .

It is a junction number, because it is equal to n+sod(n) for n = 81572189140996 and 81572189141014.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 20283236 + ... + 23969856.

Almost surely, 2^{81572189141066} is an apocalyptic number.

81572189141066 is a deficient number, since it is larger than the sum of its proper divisors (52692902999302).

81572189141066 is a wasteful number, since it uses less digits than its factorization.

81572189141066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3702746.

The product of its (nonzero) digits is 5806080, while the sum is 59.

The spelling of 81572189141066 in words is "eighty-one trillion, five hundred seventy-two billion, one hundred eighty-nine million, one hundred forty-one thousand, sixty-six".