81755411381 has 8 divisors (see below), whose sum is σ = 95960019840. Its totient is φ = 68182118928.

The previous prime is 81755411377. The next prime is 81755411417. The reversal of 81755411381 is 18311455718.

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

It is not a de Polignac number, because 81755411381 - 2² = 81755411377 is a prime.

It is a super-2 number, since 2×81755411381² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81755410381) 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, 157828721 + ... + 157829238.

It is an arithmetic number, because the mean of its divisors is an integer number (11995002480).

Almost surely, 2^81755411381 is an apocalyptic number.

It is an amenable number.

81755411381 is a deficient number, since it is larger than the sum of its proper divisors (14204608459).

81755411381 is a wasteful number, since it uses less digits than its factorization.

81755411381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 315658003.

The product of its digits is 134400, while the sum is 44.

The spelling of 81755411381 in words is "eighty-one billion, seven hundred fifty-five million, four hundred eleven thousand, three hundred eighty-one".