87635521 has 2 divisors, whose sum is σ = 87635522. Its totient is φ = 87635520.

The previous prime is 87635519. The next prime is 87635557. The reversal of 87635521 is 12553678.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87609600 + 25921 = 9360^2 + 161^2 .

It is a cyclic number.

It is not a de Polignac number, because 87635521 - 2¹ = 87635519 is a prime.

Together with 87635519, it forms a pair of twin primes.

It is equal to p_5087908 and since 87635521 and 5087908 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (87635501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43817760 + 43817761.

It is an arithmetic number, because the mean of its divisors is an integer number (43817761).

Almost surely, 2^87635521 is an apocalyptic number.

It is an amenable number.

87635521 is a deficient number, since it is larger than the sum of its proper divisors (1).

87635521 is an equidigital number, since it uses as much as digits as its factorization.

87635521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 50400, while the sum is 37.

The square root of 87635521 is about 9361.3845663983. The cubic root of 87635521 is about 444.1810819551.

The spelling of 87635521 in words is "eighty-seven million, six hundred thirty-five thousand, five hundred twenty-one".