81362167549 has 8 divisors (see below), whose sum is σ = 87625169240. Its totient is φ = 75099790656.

The previous prime is 81362167547. The next prime is 81362167559. The reversal of 81362167549 is 94576126318.

It can be written as a sum of positive squares in 4 ways, for example, as 13725762649 + 67636404900 = 117157^2 + 260070^2 .

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 81362167549 - 2¹ = 81362167547 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81362167496 and 81362167505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81362167541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 134287 + ... + 425155.

It is an arithmetic number, because the mean of its divisors is an integer number (10953146155).

Almost surely, 2^81362167549 is an apocalyptic number.

It is an amenable number.

81362167549 is a deficient number, since it is larger than the sum of its proper divisors (6263001691).

81362167549 is a wasteful number, since it uses less digits than its factorization.

81362167549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312399.

The product of its digits is 2177280, while the sum is 52.

The spelling of 81362167549 in words is "eighty-one billion, three hundred sixty-two million, one hundred sixty-seven thousand, five hundred forty-nine".