81451488 has 96 divisors (see below), whose sum is σ = 234329760. Its totient is φ = 24657920.

The previous prime is 81451483. The next prime is 81451501. The reversal of 81451488 is 88415418.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81451481) 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, 46468 + ... + 48188.

It is an arithmetic number, because the mean of its divisors is an integer number (2440935).

Almost surely, 2^81451488 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 81451488, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117164880).

81451488 is an abundant number, since it is smaller than the sum of its proper divisors (152878272).

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

81451488 is a wasteful number, since it uses less digits than its factorization.

81451488 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1780 (or 1772 counting only the distinct ones).

The product of its digits is 40960, while the sum is 39.

The square root of 81451488 is about 9025.0478115077. The cubic root of 81451488 is about 433.4772813025.

The spelling of 81451488 in words is "eighty-one million, four hundred fifty-one thousand, four hundred eighty-eight".