81987846587 has 2 divisors, whose sum is σ = 81987846588. Its totient is φ = 81987846586.

The previous prime is 81987846569. The next prime is 81987846631. The reversal of 81987846587 is 78564878918.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81987846587 - 2⁸ = 81987846331 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81987846587.

It is not a weakly prime, because it can be changed into another prime (81987846487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40993923293 + 40993923294.

It is an arithmetic number, because the mean of its divisors is an integer number (40993923294).

Almost surely, 2^81987846587 is an apocalyptic number.

81987846587 is a deficient number, since it is larger than the sum of its proper divisors (1).

81987846587 is an equidigital number, since it uses as much as digits as its factorization.

81987846587 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216760320, while the sum is 71.

The spelling of 81987846587 in words is "eighty-one billion, nine hundred eighty-seven million, eight hundred forty-six thousand, five hundred eighty-seven".