87251920709 has 8 divisors (see below), whose sum is σ = 90611823960. Its totient is φ = 83915431936.

The previous prime is 87251920699. The next prime is 87251920801. The reversal of 87251920709 is 90702915278.

It can be written as a sum of positive squares in 4 ways, for example, as 44329197025 + 42922723684 = 210545^2 + 207178^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-87251920709 is a prime.

It is a super-2 number, since 2×87251920709² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87251920009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5846024 + ... + 5860929.

It is an arithmetic number, because the mean of its divisors is an integer number (11326477995).

Almost surely, 2^87251920709 is an apocalyptic number.

It is an amenable number.

87251920709 is a deficient number, since it is larger than the sum of its proper divisors (3359903251).

87251920709 is a wasteful number, since it uses less digits than its factorization.

87251920709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11707239.

The product of its (nonzero) digits is 635040, while the sum is 50.

The spelling of 87251920709 in words is "eighty-seven billion, two hundred fifty-one million, nine hundred twenty thousand, seven hundred nine".