81944535854 has 16 divisors (see below), whose sum is σ = 126451888992. Its totient is φ = 39808917408.

The previous prime is 81944535847. The next prime is 81944535887. The reversal of 81944535854 is 45853544918.

It is a self number, because there is not a number n which added to its sum of digits gives 81944535854.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3741809 + ... + 3763644.

It is an arithmetic number, because the mean of its divisors is an integer number (7903243062).

Almost surely, 2^81944535854 is an apocalyptic number.

81944535854 is a deficient number, since it is larger than the sum of its proper divisors (44507353138).

81944535854 is a wasteful number, since it uses less digits than its factorization.

81944535854 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7505611.

The product of its digits is 13824000, while the sum is 56.

The spelling of 81944535854 in words is "eighty-one billion, nine hundred forty-four million, five hundred thirty-five thousand, eight hundred fifty-four".