21241312087 has 2 divisors, whose sum is σ = 21241312088. Its totient is φ = 21241312086.

The previous prime is 21241312013. The next prime is 21241312193. The reversal of 21241312087 is 78021314212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21241312087 - 2²³ = 21232923479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21241312007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10620656043 + 10620656044.

It is an arithmetic number, because the mean of its divisors is an integer number (10620656044).

Almost surely, 2^21241312087 is an apocalyptic number.

21241312087 is a deficient number, since it is larger than the sum of its proper divisors (1).

21241312087 is an equidigital number, since it uses as much as digits as its factorization.

21241312087 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5376, while the sum is 31.

Adding to 21241312087 its reverse (78021314212), we get a palindrome (99262626299).

The spelling of 21241312087 in words is "twenty-one billion, two hundred forty-one million, three hundred twelve thousand, eighty-seven".