81371544654101 has 8 divisors (see below), whose sum is σ = 87736601002680. Its totient is φ = 75021589271232.

The previous prime is 81371544654019. The next prime is 81371544654121. The reversal of 81371544654101 is 10145644517318.

It can be written as a sum of positive squares in 4 ways, for example, as 1306451286001 + 80065093368100 = 1143001^2 + 8947910^2 .

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 81371544654101 - 2¹⁴ = 81371544637717 is a prime.

It is a super-2 number, since 2×81371544654101² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81371544654101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81371544654121) 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, 3775230230 + ... + 3775251783.

It is an arithmetic number, because the mean of its divisors is an integer number (10967075125335).

Almost surely, 2^{81371544654101} is an apocalyptic number.

It is an amenable number.

81371544654101 is a deficient number, since it is larger than the sum of its proper divisors (6365056348579).

81371544654101 is a wasteful number, since it uses less digits than its factorization.

81371544654101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7550482855.

The product of its (nonzero) digits is 1612800, while the sum is 50.

The spelling of 81371544654101 in words is "eighty-one trillion, three hundred seventy-one billion, five hundred forty-four million, six hundred fifty-four thousand, one hundred one".