87121841549 has 2 divisors, whose sum is σ = 87121841550. Its totient is φ = 87121841548.

The previous prime is 87121841537. The next prime is 87121841563. The reversal of 87121841549 is 94514812178.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48293139049 + 38828702500 = 219757^2 + 197050^2 .

It is a cyclic number.

It is not a de Polignac number, because 87121841549 - 2²⁰ = 87120792973 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 87121841497 and 87121841506.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87121831549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43560920774 + 43560920775.

It is an arithmetic number, because the mean of its divisors is an integer number (43560920775).

Almost surely, 2^87121841549 is an apocalyptic number.

It is an amenable number.

87121841549 is a deficient number, since it is larger than the sum of its proper divisors (1).

87121841549 is an equidigital number, since it uses as much as digits as its factorization.

87121841549 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 645120, while the sum is 50.

The spelling of 87121841549 in words is "eighty-seven billion, one hundred twenty-one million, eight hundred forty-one thousand, five hundred forty-nine".