81977603 has 4 divisors (see below), whose sum is σ = 82296840. Its totient is φ = 81658368.

The previous prime is 81977579. The next prime is 81977617. The reversal of 81977603 is 30677918.

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 81977603 - 2¹⁰ = 81976579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81977653) 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, 159233 + ... + 159746.

It is an arithmetic number, because the mean of its divisors is an integer number (20574210).

Almost surely, 2^81977603 is an apocalyptic number.

81977603 is a deficient number, since it is larger than the sum of its proper divisors (319237).

81977603 is a wasteful number, since it uses less digits than its factorization.

81977603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319236.

The product of its (nonzero) digits is 63504, while the sum is 41.

The square root of 81977603 is about 9054.1483862371. The cubic root of 81977603 is about 434.4085907670.

The spelling of 81977603 in words is "eighty-one million, nine hundred seventy-seven thousand, six hundred three".