81107819 has 8 divisors (see below), whose sum is σ = 88164720. Its totient is φ = 74167776.

The previous prime is 81107801. The next prime is 81107837. The reversal of 81107819 is 91870118.

It is an interprime number because it is at equal distance from previous prime (81107801) and next prime (81107837).

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81107819 is a prime.

It is a super-2 number, since 2×81107819² = 13156956605873522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81107419) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27764 + ... + 30545.

It is an arithmetic number, because the mean of its divisors is an integer number (11020590).

Almost surely, 2^81107819 is an apocalyptic number.

81107819 is a deficient number, since it is larger than the sum of its proper divisors (7056901).

81107819 is a wasteful number, since it uses less digits than its factorization.

81107819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58429.

The product of its (nonzero) digits is 4032, while the sum is 35.

The square root of 81107819 is about 9005.9879524681. The cubic root of 81107819 is about 432.8667636370.

The spelling of 81107819 in words is "eighty-one million, one hundred seven thousand, eight hundred nineteen".