21124213387 has 2 divisors, whose sum is σ = 21124213388. Its totient is φ = 21124213386.

The previous prime is 21124213381. The next prime is 21124213391. The reversal of 21124213387 is 78331242112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21124213387 - 2⁷ = 21124213259 is a prime.

It is not a weakly prime, because it can be changed into another prime (21124213381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562106693 + 10562106694.

It is an arithmetic number, because the mean of its divisors is an integer number (10562106694).

Almost surely, 2^21124213387 is an apocalyptic number.

21124213387 is a deficient number, since it is larger than the sum of its proper divisors (1).

21124213387 is an equidigital number, since it uses as much as digits as its factorization.

21124213387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16128, while the sum is 34.

Adding to 21124213387 its reverse (78331242112), we get a palindrome (99455455499).

The spelling of 21124213387 in words is "twenty-one billion, one hundred twenty-four million, two hundred thirteen thousand, three hundred eighty-seven".