81231055 has 8 divisors (see below), whose sum is σ = 101715552. Its totient is φ = 62159328.

The previous prime is 81231047. The next prime is 81231071. The reversal of 81231055 is 55013218.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81231055 - 2³ = 81231047 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 353064 + ... + 353293.

It is an arithmetic number, because the mean of its divisors is an integer number (12714444).

Almost surely, 2^81231055 is an apocalyptic number.

81231055 is a deficient number, since it is larger than the sum of its proper divisors (20484497).

81231055 is a wasteful number, since it uses less digits than its factorization.

81231055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 706385.

The product of its (nonzero) digits is 1200, while the sum is 25.

The square root of 81231055 is about 9012.8272478729. The cubic root of 81231055 is about 433.0858866694.

The spelling of 81231055 in words is "eighty-one million, two hundred thirty-one thousand, fifty-five".