81103855 has 16 divisors (see below), whose sum is σ = 117771840. Its totient is φ = 52342272.

The previous prime is 81103853. The next prime is 81103861. The reversal of 81103855 is 55830118.

It is a cyclic number.

It is not a de Polignac number, because 81103855 - 2¹ = 81103853 is a prime.

It is a super-2 number, since 2×81103855² = 13155670591722050, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81103853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67560 + ... + 68749.

It is an arithmetic number, because the mean of its divisors is an integer number (7360740).

Almost surely, 2^81103855 is an apocalyptic number.

81103855 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

81103855 is a deficient number, since it is larger than the sum of its proper divisors (36667985).

81103855 is a wasteful number, since it uses less digits than its factorization.

81103855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136338.

The product of its (nonzero) digits is 4800, while the sum is 31.

The square root of 81103855 is about 9005.7678739794. The cubic root of 81103855 is about 432.8597116584.

The spelling of 81103855 in words is "eighty-one million, one hundred three thousand, eight hundred fifty-five".