21442400321 has 8 divisors (see below), whose sum is σ = 22223964840. Its totient is φ = 20671469568.

The previous prime is 21442400269. The next prime is 21442400341. The reversal of 21442400321 is 12300424412.

It can be written as a sum of positive squares in 4 ways, for example, as 8568094096 + 12874306225 = 92564^2 + 113465^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21442400321 - 2³⁴ = 4262531137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21442400341) 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, 2654336 + ... + 2662401.

It is an arithmetic number, because the mean of its divisors is an integer number (2777995605).

Almost surely, 2^21442400321 is an apocalyptic number.

It is an amenable number.

21442400321 is a deficient number, since it is larger than the sum of its proper divisors (781564519).

21442400321 is a wasteful number, since it uses less digits than its factorization.

21442400321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5316883.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21442400321 its reverse (12300424412), we get a palindrome (33742824733).

The spelling of 21442400321 in words is "twenty-one billion, four hundred forty-two million, four hundred thousand, three hundred twenty-one".