81467580557 has 16 divisors (see below), whose sum is σ = 94282320384. Its totient is φ = 69571008000.

The previous prime is 81467580541. The next prime is 81467580569. The reversal of 81467580557 is 75508576418.

It is a cyclic number.

It is not a de Polignac number, because 81467580557 - 2⁴ = 81467580541 is a prime.

It is a super-2 number, since 2×81467580557² (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 (81467580457) 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 15 ways as a sum of consecutive naturals, for example, 320669 + ... + 515522.

It is an arithmetic number, because the mean of its divisors is an integer number (5892645024).

Almost surely, 2^81467580557 is an apocalyptic number.

It is an amenable number.

81467580557 is a deficient number, since it is larger than the sum of its proper divisors (12814739827).

81467580557 is a wasteful number, since it uses less digits than its factorization.

81467580557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 836740.

The product of its (nonzero) digits is 9408000, while the sum is 56.

The spelling of 81467580557 in words is "eighty-one billion, four hundred sixty-seven million, five hundred eighty thousand, five hundred fifty-seven".