81016120235 has 4 divisors (see below), whose sum is σ = 97219344288. Its totient is φ = 64812896184.

The previous prime is 81016120231. The next prime is 81016120247. The reversal of 81016120235 is 53202161018.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81016120235 - 2² = 81016120231 is a prime.

It is a super-2 number, since 2×81016120235² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81016120198 and 81016120207.

It is not an unprimeable number, because it can be changed into a prime (81016120231) 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, 8101612019 + ... + 8101612028.

It is an arithmetic number, because the mean of its divisors is an integer number (24304836072).

Almost surely, 2^81016120235 is an apocalyptic number.

81016120235 is a deficient number, since it is larger than the sum of its proper divisors (16203224053).

81016120235 is a wasteful number, since it uses less digits than its factorization.

81016120235 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16203224052.

The product of its (nonzero) digits is 2880, while the sum is 29.

The spelling of 81016120235 in words is "eighty-one billion, sixteen million, one hundred twenty thousand, two hundred thirty-five".