81808183564 has 24 divisors (see below), whose sum is σ = 151604051760. Its totient is φ = 38493321216.

The previous prime is 81808183529. The next prime is 81808183601. The reversal of 81808183564 is 46538180818.

It is a super-2 number, since 2×81808183564² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 531484 + ... + 667900.

It is an arithmetic number, because the mean of its divisors is an integer number (6316835490).

Almost surely, 2^81808183564 is an apocalyptic number.

It is an amenable number.

81808183564 is a deficient number, since it is larger than the sum of its proper divisors (69795868196).

81808183564 is a wasteful number, since it uses less digits than its factorization.

81808183564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145257 (or 145255 counting only the distinct ones).

The product of its (nonzero) digits is 1474560, while the sum is 52.

The spelling of 81808183564 in words is "eighty-one billion, eight hundred eight million, one hundred eighty-three thousand, five hundred sixty-four".