21044280451 has 2 divisors, whose sum is σ = 21044280452. Its totient is φ = 21044280450.

The previous prime is 21044280449. The next prime is 21044280457. The reversal of 21044280451 is 15408244012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21044280451 - 2¹ = 21044280449 is a prime.

Together with 21044280449, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21044280457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10522140225 + 10522140226.

It is an arithmetic number, because the mean of its divisors is an integer number (10522140226).

Almost surely, 2^21044280451 is an apocalyptic number.

21044280451 is a deficient number, since it is larger than the sum of its proper divisors (1).

21044280451 is an equidigital number, since it uses as much as digits as its factorization.

21044280451 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10240, while the sum is 31.

The spelling of 21044280451 in words is "twenty-one billion, forty-four million, two hundred eighty thousand, four hundred fifty-one".