81799258 has 8 divisors (see below), whose sum is σ = 123235380. Its totient is φ = 40720800.

The previous prime is 81799243. The next prime is 81799259. The reversal of 81799258 is 85299718.

It can be written as a sum of positive squares in 2 ways, for example, as 81775849 + 23409 = 9043^2 + 153^2 .

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

It is a super-2 number, since 2×81799258² = 13382237218701128, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81799259) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88843 + ... + 89758.

Almost surely, 2^81799258 is an apocalyptic number.

81799258 is a deficient number, since it is larger than the sum of its proper divisors (41436122).

81799258 is a wasteful number, since it uses less digits than its factorization.

81799258 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178832.

The product of its digits is 362880, while the sum is 49.

The square root of 81799258 is about 9044.2942234317. The cubic root of 81799258 is about 434.0933386000.

The spelling of 81799258 in words is "eighty-one million, seven hundred ninety-nine thousand, two hundred fifty-eight".