81741555 has 72 divisors (see below), whose sum is σ = 171046512. Its totient is φ = 37340352.

The previous prime is 81741533. The next prime is 81741571. The reversal of 81741555 is 55514718.

It is not a de Polignac number, because 81741555 - 2⁵ = 81741523 is a prime.

It is a super-4 number, since 4×81741555⁴ (a number of 33 digits) contains 4444 as substring.

It is an unprimeable number.

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 71 ways as a sum of consecutive naturals, for example, 58849 + ... + 60221.

It is an arithmetic number, because the mean of its divisors is an integer number (2375646).

Almost surely, 2^81741555 is an apocalyptic number.

81741555 is an abundant number, since it is smaller than the sum of its proper divisors (89304957).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81741555 is a wasteful number, since it uses less digits than its factorization.

81741555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1407 (or 1388 counting only the distinct ones).

The product of its digits is 28000, while the sum is 36.

The square root of 81741555 is about 9041.1036383840. The cubic root of 81741555 is about 433.9912415853.

The spelling of 81741555 in words is "eighty-one million, seven hundred forty-one thousand, five hundred fifty-five".