81924412818 has 16 divisors (see below), whose sum is σ = 164065279680. Its totient is φ = 27272061936.

The previous prime is 81924412723. The next prime is 81924412883. The reversal of 81924412818 is 81821442918.

It is a super-2 number, since 2×81924412818² (a number of 23 digits) contains 22 as substring.

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, 9013998 + ... + 9023081.

It is an arithmetic number, because the mean of its divisors is an integer number (10254079980).

Almost surely, 2^81924412818 is an apocalyptic number.

81924412818 is an abundant number, since it is smaller than the sum of its proper divisors (82140866862).

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

81924412818 is a wasteful number, since it uses less digits than its factorization.

81924412818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18037841.

The product of its digits is 294912, while the sum is 48.

The spelling of 81924412818 in words is "eighty-one billion, nine hundred twenty-four million, four hundred twelve thousand, eight hundred eighteen".