81987846631 has 2 divisors, whose sum is σ = 81987846632. Its totient is φ = 81987846630.

The previous prime is 81987846587. The next prime is 81987846649. The reversal of 81987846631 is 13664878918.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81987846631 - 2¹⁵ = 81987813863 is a prime.

It is a super-2 number, since 2×81987846631² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81987846631.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81987846671) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40993923315 + 40993923316.

It is an arithmetic number, because the mean of its divisors is an integer number (40993923316).

Almost surely, 2^81987846631 is an apocalyptic number.

81987846631 is a deficient number, since it is larger than the sum of its proper divisors (1).

81987846631 is an equidigital number, since it uses as much as digits as its factorization.

81987846631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13934592, while the sum is 61.

The spelling of 81987846631 in words is "eighty-one billion, nine hundred eighty-seven million, eight hundred forty-six thousand, six hundred thirty-one".