81557106 has 16 divisors (see below), whose sum is σ = 168739200. Its totient is φ = 26248208.

The previous prime is 81557083. The next prime is 81557107. The reversal of 81557106 is 60175518.

It is not an unprimeable number, because it can be changed into a prime (81557107) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 234186 + ... + 234533.

It is an arithmetic number, because the mean of its divisors is an integer number (10546200).

Almost surely, 2^81557106 is an apocalyptic number.

81557106 is an abundant number, since it is smaller than the sum of its proper divisors (87182094).

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

81557106 is a wasteful number, since it uses less digits than its factorization.

81557106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468753.

The product of its (nonzero) digits is 8400, while the sum is 33.

The square root of 81557106 is about 9030.8972976111. The cubic root of 81557106 is about 433.6645634503.

The spelling of 81557106 in words is "eighty-one million, five hundred fifty-seven thousand, one hundred six".