21321364451 has 2 divisors, whose sum is σ = 21321364452. Its totient is φ = 21321364450.

The previous prime is 21321364423. The next prime is 21321364459. The reversal of 21321364451 is 15446312312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21321364451 - 2¹⁸ = 21321102307 is a prime.

It is not a weakly prime, because it can be changed into another prime (21321364459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10660682225 + 10660682226.

It is an arithmetic number, because the mean of its divisors is an integer number (10660682226).

Almost surely, 2^21321364451 is an apocalyptic number.

21321364451 is a deficient number, since it is larger than the sum of its proper divisors (1).

21321364451 is an equidigital number, since it uses as much as digits as its factorization.

21321364451 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 17280, while the sum is 32.

Adding to 21321364451 its reverse (15446312312), we get a palindrome (36767676763).

The spelling of 21321364451 in words is "twenty-one billion, three hundred twenty-one million, three hundred sixty-four thousand, four hundred fifty-one".