81491541306 has 64 divisors (see below), whose sum is σ = 187152761856. Its totient is φ = 23172739200.

The previous prime is 81491541283. The next prime is 81491541323. The reversal of 81491541306 is 60314519418.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9079401 + ... + 9088371.

It is an arithmetic number, because the mean of its divisors is an integer number (2924261904).

Almost surely, 2^81491541306 is an apocalyptic number.

81491541306 is an abundant number, since it is smaller than the sum of its proper divisors (105661220550).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81491541306 is a wasteful number, since it uses less digits than its factorization.

81491541306 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9987.

The product of its (nonzero) digits is 103680, while the sum is 42.

The spelling of 81491541306 in words is "eighty-one billion, four hundred ninety-one million, five hundred forty-one thousand, three hundred six".