81914931938 has 8 divisors (see below), whose sum is σ = 140425597632. Its totient is φ = 35106399396.

The previous prime is 81914931913. The next prime is 81914931947. The reversal of 81914931938 is 83913941918.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2925533270 + ... + 2925533297.

It is an arithmetic number, because the mean of its divisors is an integer number (17553199704).

Almost surely, 2^81914931938 is an apocalyptic number.

81914931938 is a deficient number, since it is larger than the sum of its proper divisors (58510665694).

81914931938 is a wasteful number, since it uses less digits than its factorization.

81914931938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5851066576.

The product of its digits is 1679616, while the sum is 56.

The spelling of 81914931938 in words is "eighty-one billion, nine hundred fourteen million, nine hundred thirty-one thousand, nine hundred thirty-eight".