81875655 has 96 divisors (see below), whose sum is σ = 163088640. Its totient is φ = 37739520.

The previous prime is 81875641. The next prime is 81875669. The reversal of 81875655 is 55657818.

81875655 is a `hidden beast` number, since 8 + 1 + 87 + 565 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (81875641) and next prime (81875669).

It is not a de Polignac number, because 81875655 - 2⁷ = 81875527 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 81875655.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 624940 + ... + 625070.

It is an arithmetic number, because the mean of its divisors is an integer number (1698840).

Almost surely, 2^81875655 is an apocalyptic number.

81875655 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

81875655 is a deficient number, since it is larger than the sum of its proper divisors (81212985).

81875655 is a wasteful number, since it uses less digits than its factorization.

81875655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221 (or 218 counting only the distinct ones).

The product of its digits is 336000, while the sum is 45.

The square root of 81875655 is about 9048.5167292767. The cubic root of 81875655 is about 434.2284380722.

The spelling of 81875655 in words is "eighty-one million, eight hundred seventy-five thousand, six hundred fifty-five".