81557322 has 32 divisors (see below), whose sum is σ = 203364864. Its totient is φ = 21183600.

The previous prime is 81557321. The next prime is 81557339. The reversal of 81557322 is 22375518.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (81557321) 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, 87804 + ... + 88727.

It is an arithmetic number, because the mean of its divisors is an integer number (6355152).

Almost surely, 2^81557322 is an apocalyptic number.

81557322 is an abundant number, since it is smaller than the sum of its proper divisors (121807542).

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

81557322 is a wasteful number, since it uses less digits than its factorization.

81557322 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176554.

The product of its digits is 16800, while the sum is 33.

The square root of 81557322 is about 9030.9092565478. The cubic root of 81557322 is about 433.6649462964.

The spelling of 81557322 in words is "eighty-one million, five hundred fifty-seven thousand, three hundred twenty-two".