81080835557 has 4 divisors (see below), whose sum is σ = 81578264160. Its totient is φ = 80583406956.

The previous prime is 81080835541. The next prime is 81080835599. The reversal of 81080835557 is 75553808018.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81080835557 - 2⁴ = 81080835541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81080825557) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 248714057 + ... + 248714382.

It is an arithmetic number, because the mean of its divisors is an integer number (20394566040).

Almost surely, 2^81080835557 is an apocalyptic number.

It is an amenable number.

81080835557 is a deficient number, since it is larger than the sum of its proper divisors (497428603).

81080835557 is a wasteful number, since it uses less digits than its factorization.

81080835557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497428602.

The product of its (nonzero) digits is 1344000, while the sum is 50.

The spelling of 81080835557 in words is "eighty-one billion, eighty million, eight hundred thirty-five thousand, five hundred fifty-seven".