81855126 has 12 divisors (see below), whose sum is σ = 177352812. Its totient is φ = 27285036.

The previous prime is 81855121. The next prime is 81855127. The reversal of 81855126 is 62155818.

81855126 is a `hidden beast` number, since 81 + 8 + 551 + 26 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81855121) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2273736 + ... + 2273771.

It is an arithmetic number, because the mean of its divisors is an integer number (14779401).

Almost surely, 2^81855126 is an apocalyptic number.

81855126 is an abundant number, since it is smaller than the sum of its proper divisors (95497686).

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

81855126 is a wasteful number, since it uses less digits than its factorization.

81855126 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4547515 (or 4547512 counting only the distinct ones).

The product of its digits is 19200, while the sum is 36.

The square root of 81855126 is about 9047.3822733429. The cubic root of 81855126 is about 434.1921431127.

The spelling of 81855126 in words is "eighty-one million, eight hundred fifty-five thousand, one hundred twenty-six".