81099249 has 16 divisors (see below), whose sum is σ = 134814720. Its totient is φ = 42129360.

The previous prime is 81099233. The next prime is 81099251. The reversal of 81099249 is 94299018.

It is not a de Polignac number, because 81099249 - 2⁴ = 81099233 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81099249.

It is not an unprimeable number, because it can be changed into a prime (81099289) 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, 175309 + ... + 175770.

It is an arithmetic number, because the mean of its divisors is an integer number (8425920).

Almost surely, 2^81099249 is an apocalyptic number.

It is an amenable number.

81099249 is a deficient number, since it is larger than the sum of its proper divisors (53715471).

81099249 is a wasteful number, since it uses less digits than its factorization.

81099249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351100.

The product of its (nonzero) digits is 46656, while the sum is 42.

The square root of 81099249 is about 9005.5121453474. The cubic root of 81099249 is about 432.8515172696.

The spelling of 81099249 in words is "eighty-one million, ninety-nine thousand, two hundred forty-nine".