81227688 has 64 divisors (see below), whose sum is σ = 214579200. Its totient is φ = 25583040.

The previous prime is 81227687. The next prime is 81227689. The reversal of 81227688 is 88672218.

It is an interprime number because it is at equal distance from previous prime (81227687) and next prime (81227689).

It is not an unprimeable number, because it can be changed into a prime (81227687) 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, 30723 + ... + 33261.

It is an arithmetic number, because the mean of its divisors is an integer number (3352800).

Almost surely, 2^81227688 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81227688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107289600).

81227688 is an abundant number, since it is smaller than the sum of its proper divisors (133351512).

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

81227688 is a wasteful number, since it uses less digits than its factorization.

81227688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2622 (or 2618 counting only the distinct ones).

The product of its digits is 86016, while the sum is 42.

The square root of 81227688 is about 9012.6404566032. The cubic root of 81227688 is about 433.0799028318.

The spelling of 81227688 in words is "eighty-one million, two hundred twenty-seven thousand, six hundred eighty-eight".