81099155 has 8 divisors (see below), whose sum is σ = 97749072. Its totient is φ = 64592608.

The previous prime is 81099149. The next prime is 81099157. The reversal of 81099155 is 55199018.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81099155 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81099157) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 34592 + ... + 36861.

It is an arithmetic number, because the mean of its divisors is an integer number (12218634).

Almost surely, 2^81099155 is an apocalyptic number.

81099155 is a deficient number, since it is larger than the sum of its proper divisors (16649917).

81099155 is a wasteful number, since it uses less digits than its factorization.

81099155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71685.

The product of its (nonzero) digits is 16200, while the sum is 38.

The square root of 81099155 is about 9005.5069263201. The cubic root of 81099155 is about 432.8513500339.

The spelling of 81099155 in words is "eighty-one million, ninety-nine thousand, one hundred fifty-five".