81610181546 has 8 divisors (see below), whose sum is σ = 122613678180. Its totient is φ = 40738955488.

The previous prime is 81610181519. The next prime is 81610181551. The reversal of 81610181546 is 64518101618.

It can be written as a sum of positive squares in 2 ways, for example, as 81244951225 + 365230321 = 285035^2 + 19111^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33066101 + ... + 33068568.

Almost surely, 2^81610181546 is an apocalyptic number.

81610181546 is a deficient number, since it is larger than the sum of its proper divisors (41003496634).

81610181546 is a wasteful number, since it uses less digits than its factorization.

81610181546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66135288.

The product of its (nonzero) digits is 46080, while the sum is 41.

The spelling of 81610181546 in words is "eighty-one billion, six hundred ten million, one hundred eighty-one thousand, five hundred forty-six".