81169078 has 4 divisors (see below), whose sum is σ = 121753620. Its totient is φ = 40584538.

The previous prime is 81169069. The next prime is 81169087. The reversal of 81169078 is 87096118.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87096118 = 2 ⋅43548059.

It is an interprime number because it is at equal distance from previous prime (81169069) and next prime (81169087).

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 81169078.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20292268 + ... + 20292271.

It is an arithmetic number, because the mean of its divisors is an integer number (30438405).

Almost surely, 2^81169078 is an apocalyptic number.

81169078 is a deficient number, since it is larger than the sum of its proper divisors (40584542).

81169078 is a wasteful number, since it uses less digits than its factorization.

81169078 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40584541.

The product of its (nonzero) digits is 24192, while the sum is 40.

The square root of 81169078 is about 9009.3883255191. The cubic root of 81169078 is about 432.9757145466.

The spelling of 81169078 in words is "eighty-one million, one hundred sixty-nine thousand, seventy-eight".