81537746120612 has 6 divisors (see below), whose sum is σ = 142691055711078. Its totient is φ = 40768873060304.

The previous prime is 81537746120591. The next prime is 81537746120669. The reversal of 81537746120612 is 21602164773518.

81537746120612 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 81414240264256 + 123505856356 = 9022984^2 + 351434^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10192218265073 + ... + 10192218265080.

It is an arithmetic number, because the mean of its divisors is an integer number (23781842618513).

Almost surely, 2^{81537746120612} is an apocalyptic number.

It is an amenable number.

81537746120612 is a deficient number, since it is larger than the sum of its proper divisors (61153309590466).

81537746120612 is a wasteful number, since it uses less digits than its factorization.

81537746120612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20384436530157 (or 20384436530155 counting only the distinct ones).

The product of its (nonzero) digits is 3386880, while the sum is 53.

The spelling of 81537746120612 in words is "eighty-one trillion, five hundred thirty-seven billion, seven hundred forty-six million, one hundred twenty thousand, six hundred twelve".