81582193845 has 16 divisors (see below), whose sum is σ = 145035011520. Its totient is φ = 43510503312.

The previous prime is 81582193829. The next prime is 81582193867. The reversal of 81582193845 is 54839128518.

81582193845 is a `hidden beast` number, since 8 + 1 + 582 + 19 + 3 + 8 + 45 = 666.

It is not a de Polignac number, because 81582193845 - 2⁴ = 81582193829 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81582193791 and 81582193800.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 302156139 + ... + 302156408.

It is an arithmetic number, because the mean of its divisors is an integer number (9064688220).

Almost surely, 2^81582193845 is an apocalyptic number.

It is an amenable number.

81582193845 is a deficient number, since it is larger than the sum of its proper divisors (63452817675).

81582193845 is a wasteful number, since it uses less digits than its factorization.

81582193845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 604312561 (or 604312555 counting only the distinct ones).

The product of its digits is 2764800, while the sum is 54.

The spelling of 81582193845 in words is "eighty-one billion, five hundred eighty-two million, one hundred ninety-three thousand, eight hundred forty-five".