81081845 has 16 divisors (see below), whose sum is σ = 105192192. Its totient is φ = 59641920.

The previous prime is 81081841. The next prime is 81081853. The reversal of 81081845 is 54818018.

It is not a de Polignac number, because 81081845 - 2² = 81081841 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81081841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15314 + ... + 19916.

It is an arithmetic number, because the mean of its divisors is an integer number (6574512).

Almost surely, 2^81081845 is an apocalyptic number.

It is an amenable number.

81081845 is a deficient number, since it is larger than the sum of its proper divisors (24110347).

81081845 is a wasteful number, since it uses less digits than its factorization.

81081845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4892.

The product of its (nonzero) digits is 10240, while the sum is 35.

The square root of 81081845 is about 9004.5457964297. The cubic root of 81081845 is about 432.8205515625.

The spelling of 81081845 in words is "eighty-one million, eighty-one thousand, eight hundred forty-five".