81245855 has 4 divisors (see below), whose sum is σ = 97495032. Its totient is φ = 64996680.

The previous prime is 81245833. The next prime is 81245863. The reversal of 81245855 is 55854218.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 81245855 - 2¹⁴ = 81229471 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 3 ways as a sum of consecutive naturals, for example, 8124581 + ... + 8124590.

It is an arithmetic number, because the mean of its divisors is an integer number (24373758).

Almost surely, 2^81245855 is an apocalyptic number.

81245855 is a deficient number, since it is larger than the sum of its proper divisors (16249177).

81245855 is a wasteful number, since it uses less digits than its factorization.

81245855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16249176.

The product of its digits is 64000, while the sum is 38.

The square root of 81245855 is about 9013.6482624962. The cubic root of 81245855 is about 433.1121872917.

The spelling of 81245855 in words is "eighty-one million, two hundred forty-five thousand, eight hundred fifty-five".