81396828 has 18 divisors (see below), whose sum is σ = 205753184. Its totient is φ = 27132264.

The previous prime is 81396827. The next prime is 81396829. The reversal of 81396828 is 82869318.

It is an interprime number because it is at equal distance from previous prime (81396827) and next prime (81396829).

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81396827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1130476 + ... + 1130547.

Almost surely, 2^81396828 is an apocalyptic number.

It is an amenable number.

81396828 is an abundant number, since it is smaller than the sum of its proper divisors (124356356).

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

81396828 is a wasteful number, since it uses less digits than its factorization.

81396828 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2261033 (or 2261028 counting only the distinct ones).

The product of its digits is 165888, while the sum is 45.

The square root of 81396828 is about 9022.0190644888. The cubic root of 81396828 is about 433.3802944503.

The spelling of 81396828 in words is "eighty-one million, three hundred ninety-six thousand, eight hundred twenty-eight".