81100775 has 12 divisors (see below), whose sum is σ = 114931632. Its totient is φ = 55611840.

The previous prime is 81100729. The next prime is 81100787. The reversal of 81100775 is 57700118.

It is not a de Polignac number, because 81100775 - 2¹⁴ = 81084391 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 231542 + ... + 231891.

It is an arithmetic number, because the mean of its divisors is an integer number (9577636).

Almost surely, 2^81100775 is an apocalyptic number.

81100775 is a deficient number, since it is larger than the sum of its proper divisors (33830857).

81100775 is a wasteful number, since it uses less digits than its factorization.

81100775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 463450 (or 463445 counting only the distinct ones).

The product of its (nonzero) digits is 1960, while the sum is 29.

The square root of 81100775 is about 9005.5968708354. The cubic root of 81100775 is about 432.8542321623.

The spelling of 81100775 in words is "eighty-one million, one hundred thousand, seven hundred seventy-five".