81523950 has 72 divisors (see below), whose sum is σ = 208314792. Its totient is φ = 21098880.

The previous prime is 81523943. The next prime is 81523973. The reversal of 81523950 is 5932518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 205152 + ... + 205548.

It is an arithmetic number, because the mean of its divisors is an integer number (2893261).

Almost surely, 2^81523950 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81523950, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (104157396).

81523950 is an abundant number, since it is smaller than the sum of its proper divisors (126790842).

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

81523950 is a wasteful number, since it uses less digits than its factorization.

81523950 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 486 (or 444 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 33.

The square root of 81523950 is about 9029.0614130152. The cubic root of 81523950 is about 433.6057885546.

The spelling of 81523950 in words is "eighty-one million, five hundred twenty-three thousand, nine hundred fifty".