21378441601 has 8 divisors (see below), whose sum is σ = 23583981600. Its totient is φ = 19216575840.

The previous prime is 21378441599. The next prime is 21378441607. The reversal of 21378441601 is 10614487312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21378441601 - 2¹ = 21378441599 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21378441607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10917531 + ... + 10919488.

It is an arithmetic number, because the mean of its divisors is an integer number (2947997700).

Almost surely, 2^21378441601 is an apocalyptic number.

It is an amenable number.

21378441601 is a deficient number, since it is larger than the sum of its proper divisors (2205539999).

21378441601 is a wasteful number, since it uses less digits than its factorization.

21378441601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21837119.

The product of its (nonzero) digits is 32256, while the sum is 37.

The spelling of 21378441601 in words is "twenty-one billion, three hundred seventy-eight million, four hundred forty-one thousand, six hundred one".