81906822 has 32 divisors (see below), whose sum is σ = 182770560. Its totient is φ = 27189000.

The previous prime is 81906719. The next prime is 81906823. The reversal of 81906822 is 22860918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81906823) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10533 + ... + 16575.

It is an arithmetic number, because the mean of its divisors is an integer number (5711580).

Almost surely, 2^81906822 is an apocalyptic number.

81906822 is an abundant number, since it is smaller than the sum of its proper divisors (100863738).

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

81906822 is a wasteful number, since it uses less digits than its factorization.

81906822 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6305 (or 6299 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 81906822 is about 9050.2387813803. The cubic root of 81906822 is about 434.2835292583.

It can be divided in two parts, 81906 and 822, that added together give a palindrome (82728).

The spelling of 81906822 in words is "eighty-one million, nine hundred six thousand, eight hundred twenty-two".