81798249 has 32 divisors (see below), whose sum is σ = 125798400. Its totient is φ = 46854720.

The previous prime is 81798247. The next prime is 81798251. The reversal of 81798249 is 94289718.

It is an interprime number because it is at equal distance from previous prime (81798247) and next prime (81798251).

It is not a de Polignac number, because 81798249 - 2¹ = 81798247 is a prime.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 81798198 and 81798207.

It is not an unprimeable number, because it can be changed into a prime (81798247) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 42784 + ... + 44654.

It is an arithmetic number, because the mean of its divisors is an integer number (3931200).

Almost surely, 2^81798249 is an apocalyptic number.

It is an amenable number.

81798249 is a deficient number, since it is larger than the sum of its proper divisors (44000151).

81798249 is a wasteful number, since it uses less digits than its factorization.

81798249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1965.

The product of its digits is 290304, while the sum is 48.

The square root of 81798249 is about 9044.2384422349. The cubic root of 81798249 is about 434.0915537347.

The spelling of 81798249 in words is "eighty-one million, seven hundred ninety-eight thousand, two hundred forty-nine".