81776655 has 32 divisors (see below), whose sum is σ = 147859200. Its totient is φ = 42870816.

The previous prime is 81776641. The next prime is 81776657. The reversal of 81776655 is 55667718.

It is not a de Polignac number, because 81776655 - 2¹⁴ = 81760271 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 81776655.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81776657) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2832 + ... + 13098.

It is an arithmetic number, because the mean of its divisors is an integer number (4620600).

Almost surely, 2^81776655 is an apocalyptic number.

81776655 is a deficient number, since it is larger than the sum of its proper divisors (66082545).

81776655 is a wasteful number, since it uses less digits than its factorization.

81776655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10340 (or 10334 counting only the distinct ones).

The product of its digits is 352800, while the sum is 45.

The square root of 81776655 is about 9043.0445647470. The cubic root of 81776655 is about 434.0533516211.

The spelling of 81776655 in words is "eighty-one million, seven hundred seventy-six thousand, six hundred fifty-five".