21233021387 has 2 divisors, whose sum is σ = 21233021388. Its totient is φ = 21233021386.

The previous prime is 21233021323. The next prime is 21233021393. The reversal of 21233021387 is 78312033212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21233021387 - 2⁶ = 21233021323 is a prime.

It is not a weakly prime, because it can be changed into another prime (21233021087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10616510693 + 10616510694.

It is an arithmetic number, because the mean of its divisors is an integer number (10616510694).

Almost surely, 2^21233021387 is an apocalyptic number.

21233021387 is a deficient number, since it is larger than the sum of its proper divisors (1).

21233021387 is an equidigital number, since it uses as much as digits as its factorization.

21233021387 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 32.

Adding to 21233021387 its reverse (78312033212), we get a palindrome (99545054599).

The spelling of 21233021387 in words is "twenty-one billion, two hundred thirty-three million, twenty-one thousand, three hundred eighty-seven".