87123557 has 4 divisors (see below), whose sum is σ = 88021836. Its totient is φ = 86225280.

The previous prime is 87123541. The next prime is 87123559. The reversal of 87123557 is 75532178.

It is a happy number.

It is a Cunningham number, because it is equal to 9334²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 39112516 + 48011041 = 6254^2 + 6929^2 .

It is a cyclic number.

It is not a de Polignac number, because 87123557 - 2⁴ = 87123541 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 87123557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87123559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 448994 + ... + 449187.

It is an arithmetic number, because the mean of its divisors is an integer number (22005459).

Almost surely, 2^87123557 is an apocalyptic number.

It is an amenable number.

87123557 is a deficient number, since it is larger than the sum of its proper divisors (898279).

87123557 is an equidigital number, since it uses as much as digits as its factorization.

87123557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 898278.

The product of its digits is 58800, while the sum is 38.

The square root of 87123557 is about 9334.0000535676. Note that the first 4 decimals coincide. The cubic root of 87123557 is about 443.3144280605.

The spelling of 87123557 in words is "eighty-seven million, one hundred twenty-three thousand, five hundred fifty-seven".