21403112042321 has 4 divisors (see below), whose sum is σ = 21660980862192. Its totient is φ = 21145243222452.

The previous prime is 21403112042293. The next prime is 21403112042327. The reversal of 21403112042321 is 12324021130412.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21403112042321 is a prime.

It is a super-2 number, since 2×21403112042321² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21403112042327) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128934409811 + ... + 128934409976.

It is an arithmetic number, because the mean of its divisors is an integer number (5415245215548).

Almost surely, 2^{21403112042321} is an apocalyptic number.

It is an amenable number.

21403112042321 is a deficient number, since it is larger than the sum of its proper divisors (257868819871).

21403112042321 is an equidigital number, since it uses as much as digits as its factorization.

21403112042321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 257868819870.

The product of its (nonzero) digits is 2304, while the sum is 26.

Adding to 21403112042321 its reverse (12324021130412), we get a palindrome (33727133172733).

The spelling of 21403112042321 in words is "twenty-one trillion, four hundred three billion, one hundred twelve million, forty-two thousand, three hundred twenty-one".