81799190 has 32 divisors (see below), whose sum is σ = 161498016. Its totient is φ = 29583360.

The previous prime is 81799187. The next prime is 81799213. The reversal of 81799190 is 9199718.

It is a super-2 number, since 2×81799190² = 13382214969312200, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19304 + ... + 23156.

It is an arithmetic number, because the mean of its divisors is an integer number (5046813).

Almost surely, 2^81799190 is an apocalyptic number.

81799190 is a deficient number, since it is larger than the sum of its proper divisors (79698826).

81799190 is a wasteful number, since it uses less digits than its factorization.

81799190 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4064.

The product of its (nonzero) digits is 40824, while the sum is 44.

The square root of 81799190 is about 9044.2904641547. The cubic root of 81799190 is about 434.0932183122.

The spelling of 81799190 in words is "eighty-one million, seven hundred ninety-nine thousand, one hundred ninety".