87481021 has 2 divisors, whose sum is σ = 87481022. Its totient is φ = 87481020.

The previous prime is 87481013. The next prime is 87481027. The reversal of 87481021 is 12018478.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60295225 + 27185796 = 7765^2 + 5214^2 .

It is a cyclic number.

It is not a de Polignac number, because 87481021 - 2³ = 87481013 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87481027) 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, 43740510 + 43740511.

It is an arithmetic number, because the mean of its divisors is an integer number (43740511).

Almost surely, 2^87481021 is an apocalyptic number.

It is an amenable number.

87481021 is a deficient number, since it is larger than the sum of its proper divisors (1).

87481021 is an equidigital number, since it uses as much as digits as its factorization.

87481021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 87481021 is about 9353.1289416965. The cubic root of 87481021 is about 443.9199003978.

Adding to 87481021 its reverse (12018478), we get a palindrome (99499499).

The spelling of 87481021 in words is "eighty-seven million, four hundred eighty-one thousand, twenty-one".