87221525 has 12 divisors (see below), whose sum is σ = 108721092. Its totient is φ = 69411840.

The previous prime is 87221489. The next prime is 87221539. The reversal of 87221525 is 52512278.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 97969 + 87123556 = 313^2 + 9334^2 .

It is not a de Polignac number, because 87221525 - 2⁸ = 87221269 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 87221491 and 87221500.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 4214 + ... + 13863.

It is an arithmetic number, because the mean of its divisors is an integer number (9060091).

Almost surely, 2^87221525 is an apocalyptic number.

It is an amenable number.

87221525 is a deficient number, since it is larger than the sum of its proper divisors (21499567).

87221525 is a wasteful number, since it uses less digits than its factorization.

87221525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18280 (or 18275 counting only the distinct ones).

The product of its digits is 11200, while the sum is 32.

The square root of 87221525 is about 9339.2464899477. The cubic root of 87221525 is about 443.4805307033.

The spelling of 87221525 in words is "eighty-seven million, two hundred twenty-one thousand, five hundred twenty-five".