21378441607 has 2 divisors, whose sum is σ = 21378441608. Its totient is φ = 21378441606.

The previous prime is 21378441599. The next prime is 21378441631. The reversal of 21378441607 is 70614487312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21378441607 - 2³ = 21378441599 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21378421607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10689220803 + 10689220804.

It is an arithmetic number, because the mean of its divisors is an integer number (10689220804).

Almost surely, 2^21378441607 is an apocalyptic number.

21378441607 is a deficient number, since it is larger than the sum of its proper divisors (1).

21378441607 is an equidigital number, since it uses as much as digits as its factorization.

21378441607 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 225792, while the sum is 43.

The spelling of 21378441607 in words is "twenty-one billion, three hundred seventy-eight million, four hundred forty-one thousand, six hundred seven".