87444289721 has 8 divisors (see below), whose sum is σ = 87790408200. Its totient is φ = 87098327680.

The previous prime is 87444289717. The next prime is 87444289753. The reversal of 87444289721 is 12798244478.

It can be written as a sum of positive squares in 4 ways, for example, as 14217223696 + 73227066025 = 119236^2 + 270605^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 87444289721 - 2² = 87444289717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87444289781) 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 in 7 ways as a sum of consecutive naturals, for example, 1152485 + ... + 1226013.

It is an arithmetic number, because the mean of its divisors is an integer number (10973801025).

Almost surely, 2^87444289721 is an apocalyptic number.

It is an amenable number.

87444289721 is a deficient number, since it is larger than the sum of its proper divisors (346118479).

87444289721 is a wasteful number, since it uses less digits than its factorization.

87444289721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78219.

The product of its digits is 7225344, while the sum is 56.

The spelling of 87444289721 in words is "eighty-seven billion, four hundred forty-four million, two hundred eighty-nine thousand, seven hundred twenty-one".