81657603 has 6 divisors (see below), whose sum is σ = 117949884. Its totient is φ = 54438396.

The previous prime is 81657601. The next prime is 81657619. The reversal of 81657603 is 30675618.

81657603 is a `hidden beast` number, since 81 + 6 + 576 + 0 + 3 = 666.

It is not a de Polignac number, because 81657603 - 2¹ = 81657601 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81657601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4536525 + ... + 4536542.

It is an arithmetic number, because the mean of its divisors is an integer number (19658314).

Almost surely, 2^81657603 is an apocalyptic number.

81657603 is a deficient number, since it is larger than the sum of its proper divisors (36292281).

81657603 is a wasteful number, since it uses less digits than its factorization.

81657603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9073073 (or 9073070 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 81657603 is about 9036.4596496637. The cubic root of 81657603 is about 433.8426149654.

The spelling of 81657603 in words is "eighty-one million, six hundred fifty-seven thousand, six hundred three".