81897603 has 4 divisors (see below), whose sum is σ = 109196808. Its totient is φ = 54598400.

The previous prime is 81897589. The next prime is 81897611. The reversal of 81897603 is 30679818.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81897603 - 2⁴ = 81897587 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81897203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13649598 + ... + 13649603.

It is an arithmetic number, because the mean of its divisors is an integer number (27299202).

Almost surely, 2^81897603 is an apocalyptic number.

81897603 is a deficient number, since it is larger than the sum of its proper divisors (27299205).

81897603 is a wasteful number, since it uses less digits than its factorization.

81897603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27299204.

The product of its (nonzero) digits is 72576, while the sum is 42.

The square root of 81897603 is about 9049.7294434696. The cubic root of 81897603 is about 434.2672350923.

The spelling of 81897603 in words is "eighty-one million, eight hundred ninety-seven thousand, six hundred three".