81987896 has 16 divisors (see below), whose sum is σ = 154535040. Its totient is φ = 40778560.

The previous prime is 81987887. The next prime is 81987931. The reversal of 81987896 is 69878918.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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, 25301 + ... + 28356.

It is an arithmetic number, because the mean of its divisors is an integer number (9658440).

Almost surely, 2^81987896 is an apocalyptic number.

It is an amenable number.

81987896 is a deficient number, since it is larger than the sum of its proper divisors (72547144).

81987896 is a wasteful number, since it uses less digits than its factorization.

81987896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53854 (or 53850 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 56.

The square root of 81987896 is about 9054.7167818767. The cubic root of 81987896 is about 434.4267712632.

The spelling of 81987896 in words is "eighty-one million, nine hundred eighty-seven thousand, eight hundred ninety-six".