81425888 has 48 divisors (see below), whose sum is σ = 168285600. Its totient is φ = 38708736.

The previous prime is 81425831. The next prime is 81425899. The reversal of 81425888 is 88852418.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 233138 + ... + 233486.

It is an arithmetic number, because the mean of its divisors is an integer number (3505950).

Almost surely, 2^81425888 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 81425888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (84142800).

81425888 is an abundant number, since it is smaller than the sum of its proper divisors (86859712).

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

81425888 is a wasteful number, since it uses less digits than its factorization.

81425888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 699 (or 691 counting only the distinct ones).

The product of its digits is 163840, while the sum is 44.

The square root of 81425888 is about 9023.6294250152. The cubic root of 81425888 is about 433.4318629336.

The spelling of 81425888 in words is "eighty-one million, four hundred twenty-five thousand, eight hundred eighty-eight".