81812195 has 32 divisors (see below), whose sum is σ = 107412480. Its totient is φ = 59616000.

The previous prime is 81812189. The next prime is 81812197. The reversal of 81812195 is 59121818.

It is not a de Polignac number, because 81812195 - 2²⁰ = 80763619 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81812197) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 325820 + ... + 326070.

It is an arithmetic number, because the mean of its divisors is an integer number (3356640).

Almost surely, 2^81812195 is an apocalyptic number.

81812195 is a deficient number, since it is larger than the sum of its proper divisors (25600285).

81812195 is a wasteful number, since it uses less digits than its factorization.

81812195 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395.

The product of its digits is 5760, while the sum is 35.

The square root of 81812195 is about 9045.0093974523. The cubic root of 81812195 is about 434.1162221388.

The spelling of 81812195 in words is "eighty-one million, eight hundred twelve thousand, one hundred ninety-five".