81706254018 has 16 divisors (see below), whose sum is σ = 163416116736. Its totient is φ = 27234816560.

The previous prime is 81706254011. The next prime is 81706254031. The reversal of 81706254018 is 81045260718.

It is a super-2 number, since 2×81706254018² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81706254011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 210655 + ... + 455837.

It is an arithmetic number, because the mean of its divisors is an integer number (10213507296).

Almost surely, 2^81706254018 is an apocalyptic number.

81706254018 is an abundant number, since it is smaller than the sum of its proper divisors (81709862718).

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

81706254018 is a wasteful number, since it uses less digits than its factorization.

81706254018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 300729.

The product of its (nonzero) digits is 107520, while the sum is 42.

The spelling of 81706254018 in words is "eighty-one billion, seven hundred six million, two hundred fifty-four thousand, eighteen".