81931746371 has 8 divisors (see below), whose sum is σ = 83481950160. Its totient is φ = 80381702752.

The previous prime is 81931746361. The next prime is 81931746383. The reversal of 81931746371 is 17364713918.

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

It is a cyclic number.

It is not a de Polignac number, because 81931746371 - 2¹⁰ = 81931745347 is a prime.

It is a super-2 number, since 2×81931746371² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81931746341) 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, 1702640 + ... + 1750098.

It is an arithmetic number, because the mean of its divisors is an integer number (10435243770).

Almost surely, 2^81931746371 is an apocalyptic number.

81931746371 is a deficient number, since it is larger than the sum of its proper divisors (1550203789).

81931746371 is a wasteful number, since it uses less digits than its factorization.

81931746371 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80085.

The product of its digits is 762048, while the sum is 50.

The spelling of 81931746371 in words is "eighty-one billion, nine hundred thirty-one million, seven hundred forty-six thousand, three hundred seventy-one".