81897111123 has 8 divisors (see below), whose sum is σ = 109207098000. Its totient is φ = 54592599168.

The previous prime is 81897111113. The next prime is 81897111139. The reversal of 81897111123 is 32111179818.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81897111123 - 2³⁶ = 13177634387 is a prime.

It is a super-2 number, since 2×81897111123² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81897111113) 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 7 ways as a sum of consecutive naturals, for example, 1333698 + ... + 1393751.

It is an arithmetic number, because the mean of its divisors is an integer number (13650887250).

Almost surely, 2^81897111123 is an apocalyptic number.

81897111123 is a deficient number, since it is larger than the sum of its proper divisors (27309986877).

81897111123 is a wasteful number, since it uses less digits than its factorization.

81897111123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2737461.

The product of its digits is 24192, while the sum is 42.

The spelling of 81897111123 in words is "eighty-one billion, eight hundred ninety-seven million, one hundred eleven thousand, one hundred twenty-three".