81814019 has 16 divisors (see below), whose sum is σ = 99360000. Its totient is φ = 65803104.

The previous prime is 81814009. The next prime is 81814021. The reversal of 81814019 is 91041818.

It is a cyclic number.

It is not a de Polignac number, because 81814019 - 2⁴ = 81814003 is a prime.

It is a super-2 number, since 2×81814019² = 13387067409864722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81814009) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11357 + ... + 17105.

It is an arithmetic number, because the mean of its divisors is an integer number (6210000).

Almost surely, 2^81814019 is an apocalyptic number.

81814019 is a deficient number, since it is larger than the sum of its proper divisors (17545981).

81814019 is a wasteful number, since it uses less digits than its factorization.

81814019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5882.

The product of its (nonzero) digits is 2304, while the sum is 32.

The square root of 81814019 is about 9045.1102259729. The cubic root of 81814019 is about 434.1194483168.

The spelling of 81814019 in words is "eighty-one million, eight hundred fourteen thousand, nineteen".