21333403387 has 2 divisors, whose sum is σ = 21333403388. Its totient is φ = 21333403386.

The previous prime is 21333403381. The next prime is 21333403439. The reversal of 21333403387 is 78330433312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21333403387 - 2¹¹ = 21333401339 is a prime.

It is a super-2 number, since 2×21333403387² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21333403381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10666701693 + 10666701694.

It is an arithmetic number, because the mean of its divisors is an integer number (10666701694).

Almost surely, 2^21333403387 is an apocalyptic number.

21333403387 is a deficient number, since it is larger than the sum of its proper divisors (1).

21333403387 is an equidigital number, since it uses as much as digits as its factorization.

21333403387 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108864, while the sum is 37.

Adding to 21333403387 its reverse (78330433312), we get a palindrome (99663836699).

The spelling of 21333403387 in words is "twenty-one billion, three hundred thirty-three million, four hundred three thousand, three hundred eighty-seven".