81079111 has 4 divisors (see below), whose sum is σ = 81216432. Its totient is φ = 80941792.

The previous prime is 81079109. The next prime is 81079133. The reversal of 81079111 is 11197018.

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 81079111 - 2¹ = 81079109 is a prime.

It is a super-3 number, since 3×81079111³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81079111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81079151) 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, 67771 + ... + 68956.

It is an arithmetic number, because the mean of its divisors is an integer number (20304108).

Almost surely, 2^81079111 is an apocalyptic number.

81079111 is a deficient number, since it is larger than the sum of its proper divisors (137321).

81079111 is a wasteful number, since it uses less digits than its factorization.

81079111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137320.

The product of its (nonzero) digits is 504, while the sum is 28.

The square root of 81079111 is about 9004.3939829397. The cubic root of 81079111 is about 432.8156867469.

The spelling of 81079111 in words is "eighty-one million, seventy-nine thousand, one hundred eleven".