81987110 has 16 divisors (see below), whose sum is σ = 147682656. Its totient is φ = 32771328.

The previous prime is 81987097. The next prime is 81987119. The reversal of 81987110 is 1178918.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81987119) 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 7 ways as a sum of consecutive naturals, for example, 20927 + ... + 24533.

It is an arithmetic number, because the mean of its divisors is an integer number (9230166).

Almost surely, 2^81987110 is an apocalyptic number.

81987110 is a deficient number, since it is larger than the sum of its proper divisors (65695546).

81987110 is a wasteful number, since it uses less digits than its factorization.

81987110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5887.

The product of its (nonzero) digits is 4032, while the sum is 35.

The square root of 81987110 is about 9054.6733789795. The cubic root of 81987110 is about 434.4253830074.

The spelling of 81987110 in words is "eighty-one million, nine hundred eighty-seven thousand, one hundred ten".