81924412819 has 32 divisors (see below), whose sum is σ = 91884948480. Its totient is φ = 72587699712.

The previous prime is 81924412723. The next prime is 81924412883. The reversal of 81924412819 is 91821442918.

It is a de Polignac number, because none of the positive numbers 2^k-81924412819 is a prime.

It is a super-2 number, since 2×81924412819² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81924412519) by changing a digit.

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, 74273622 + ... + 74274724.

It is an arithmetic number, because the mean of its divisors is an integer number (2871404640).

Almost surely, 2^81924412819 is an apocalyptic number.

81924412819 is a deficient number, since it is larger than the sum of its proper divisors (9960535661).

81924412819 is a wasteful number, since it uses less digits than its factorization.

81924412819 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2379.

The product of its digits is 331776, while the sum is 49.

The spelling of 81924412819 in words is "eighty-one billion, nine hundred twenty-four million, four hundred twelve thousand, eight hundred nineteen".