81532000 has 192 divisors, whose sum is σ = 233513280. Its totient is φ = 27648000.

The previous prime is 81531943. The next prime is 81532001. The reversal of 81532000 is 23518.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81532001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 747946 + ... + 748054.

It is an arithmetic number, because the mean of its divisors is an integer number (1216215).

Almost surely, 2^81532000 is an apocalyptic number.

81532000 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81532000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116756640).

81532000 is an abundant number, since it is smaller than the sum of its proper divisors (151981280).

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

81532000 is a wasteful number, since it uses less digits than its factorization.

81532000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162 (or 144 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 81532000 is about 9029.5071847804. The cubic root of 81532000 is about 433.6200600733.

Adding to 81532000 its reverse (23518), we get a palindrome (81555518).

It can be divided in two parts, 8153 and 2000, that added together give a triangular number (10153 = T₁₄₂).

The spelling of 81532000 in words is "eighty-one million, five hundred thirty-two thousand".