81062257105 has 32 divisors (see below), whose sum is σ = 107603627040. Its totient is φ = 58346803200.

The previous prime is 81062257063. The next prime is 81062257123. The reversal of 81062257105 is 50175226018.

It can be written as a sum of positive squares in 16 ways, for example, as 2307937681 + 78754319424 = 48041^2 + 280632^2 .

It is a de Polignac number, because none of the positive numbers 2^k-81062257105 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 86167 + ... + 411763.

It is an arithmetic number, because the mean of its divisors is an integer number (3362613345).

Almost surely, 2^81062257105 is an apocalyptic number.

81062257105 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

81062257105 is a deficient number, since it is larger than the sum of its proper divisors (26541369935).

81062257105 is a wasteful number, since it uses less digits than its factorization.

81062257105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325749.

The product of its (nonzero) digits is 33600, while the sum is 37.

The spelling of 81062257105 in words is "eighty-one billion, sixty-two million, two hundred fifty-seven thousand, one hundred five".