81557352 has 96 divisors (see below), whose sum is σ = 228571200. Its totient is φ = 26258688.

The previous prime is 81557339. The next prime is 81557363. The reversal of 81557352 is 25375518.

81557352 is a `hidden beast` number, since 81 + 5 + 573 + 5 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

Its product of digits (42000) is a multiple of the sum of its prime divisors (400).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 309973 + ... + 310235.

It is an arithmetic number, because the mean of its divisors is an integer number (2380950).

Almost surely, 2^81557352 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 81557352, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114285600).

81557352 is an abundant number, since it is smaller than the sum of its proper divisors (147013848).

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

81557352 is a wasteful number, since it uses less digits than its factorization.

81557352 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407 (or 400 counting only the distinct ones).

The product of its digits is 42000, while the sum is 36.

The square root of 81557352 is about 9030.9109175099. The cubic root of 81557352 is about 433.6649994694.

The spelling of 81557352 in words is "eighty-one million, five hundred fifty-seven thousand, three hundred fifty-two".