81557016 has 16 divisors (see below), whose sum is σ = 203892600. Its totient is φ = 27185664.

The previous prime is 81557009. The next prime is 81557027. The reversal of 81557016 is 61075518.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1699081 + ... + 1699128.

Almost surely, 2^81557016 is an apocalyptic number.

It is an amenable number.

81557016 is an abundant number, since it is smaller than the sum of its proper divisors (122335584).

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

81557016 is a wasteful number, since it uses less digits than its factorization.

81557016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3398218 (or 3398214 counting only the distinct ones).

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

The square root of 81557016 is about 9030.8923147162. The cubic root of 81557016 is about 433.6644039309.

The spelling of 81557016 in words is "eighty-one million, five hundred fifty-seven thousand, sixteen".