81811883373 has 16 divisors (see below), whose sum is σ = 121244371776. Its totient is φ = 48647431040.

The previous prime is 81811883357. The next prime is 81811883423. The reversal of 81811883373 is 37338811818.

It is a cyclic number.

It is not a de Polignac number, because 81811883373 - 2⁴ = 81811883357 is a prime.

It is a super-2 number, since 2×81811883373² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81811883323) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23386440 + ... + 23389937.

It is an arithmetic number, because the mean of its divisors is an integer number (7577773236).

Almost surely, 2^81811883373 is an apocalyptic number.

It is an amenable number.

81811883373 is a deficient number, since it is larger than the sum of its proper divisors (39432488403).

81811883373 is a wasteful number, since it uses less digits than its factorization.

81811883373 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46776444.

The product of its digits is 774144, while the sum is 51.

The spelling of 81811883373 in words is "eighty-one billion, eight hundred eleven million, eight hundred eighty-three thousand, three hundred seventy-three".