81958247745 has 32 divisors (see below), whose sum is σ = 144098628480. Its totient is φ = 39447267840.

The previous prime is 81958247731. The next prime is 81958247801. The reversal of 81958247745 is 54774285918.

It is not a de Polignac number, because 81958247745 - 2⁸ = 81958247489 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1790230 + ... + 1835439.

It is an arithmetic number, because the mean of its divisors is an integer number (4503082140).

Almost surely, 2^81958247745 is an apocalyptic number.

It is an amenable number.

81958247745 is a deficient number, since it is larger than the sum of its proper divisors (62140380735).

81958247745 is a wasteful number, since it uses less digits than its factorization.

81958247745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3625825.

The product of its digits is 22579200, while the sum is 60.

The spelling of 81958247745 in words is "eighty-one billion, nine hundred fifty-eight million, two hundred forty-seven thousand, seven hundred forty-five".