87421 has 2 divisors, whose sum is σ = 87422. Its totient is φ = 87420.

The previous prime is 87407. The next prime is 87427. The reversal of 87421 is 12478.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81796 + 5625 = 286^2 + 75^2 .

It is a cyclic number.

It is not a de Polignac number, because 87421 - 2⁷ = 87293 is a prime.

It is a plaindrome in base 16.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 87392 and 87401.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43710 + 43711.

It is an arithmetic number, because the mean of its divisors is an integer number (43711).

2⁸⁷⁴²¹ is an apocalyptic number.

It is an amenable number.

87421 is a deficient number, since it is larger than the sum of its proper divisors (1).

87421 is an equidigital number, since it uses as much as digits as its factorization.

87421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 448, while the sum is 22.

The square root of 87421 is about 295.6704246285. The cubic root of 87421 is about 44.3818352230.

Adding to 87421 its reverse (12478), we get a palindrome (99899).

The spelling of 87421 in words is "eighty-seven thousand, four hundred twenty-one".