87162821 has 2 divisors, whose sum is σ = 87162822. Its totient is φ = 87162820.

The previous prime is 87162781. The next prime is 87162851. The reversal of 87162821 is 12826178.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84897796 + 2265025 = 9214^2 + 1505^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87162821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87162851) 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 as a sum of consecutive naturals, namely, 43581410 + 43581411.

It is an arithmetic number, because the mean of its divisors is an integer number (43581411).

Almost surely, 2^87162821 is an apocalyptic number.

It is an amenable number.

87162821 is a deficient number, since it is larger than the sum of its proper divisors (1).

87162821 is an equidigital number, since it uses as much as digits as its factorization.

87162821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10752, while the sum is 35.

The square root of 87162821 is about 9336.1030949749. The cubic root of 87162821 is about 443.3810142748.

Adding to 87162821 its reverse (12826178), we get a palindrome (99988999).

The spelling of 87162821 in words is "eighty-seven million, one hundred sixty-two thousand, eight hundred twenty-one".